SAT · Algebra
Turn a sentence into an equation in one variable.
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Tip: Search these exact Question IDs in the College Board SAT Suite Question Bank, Algebra, skill Linear equations in one variable for full questions and rationales.
One sentence. Name the variable, then write the equation.
“9 more than n” is n + 9.
is means =.
n + 9 = 24
Answer: n + 9 = 24
The sum of n and 17 is n + 17.
n + 17 = 41
Answer: n + 17 = 41
The difference of n and 38 is n − 38.
n − 38 = 11
Answer: n − 38 = 11
The quotient of n and 7 is n7.
n7 = 8
Answer: n7 = 8
n decreased by 15 is n − 15.
n − 15 = 22
Answer: n − 15 = 22
Half of n is n2.
n2 = 16
Answer: n2 = 16
n increased by 9 is n + 9.
n + 9 = 31
Answer: n + 9 = 31
The product of n and 9 is 9n.
9n = 72
Answer: 9n = 72
n squared is n².
n² = 81
Answer: n² = 81
Twice n is 2n.
2n = 28
Answer: 2n = 28
The quotient of 42 and n is 42n.
42n = 6
Answer: 42n = 6
n cubed is n³.
n³ = 64
Answer: n³ = 64
8 subtracted from n is n − 8.
n − 8 = 19
Answer: n − 8 = 19
Four times n is 4n.
Increased by 7 is 4n + 7.
4n + 7 = 35
Answer: 4n + 7 = 35
Five times n is 5n.
9 subtracted from that is 5n − 9.
5n − 9 = 16
Answer: 5n − 9 = 16
The sum of 10 and 5 is 10 + 5.
The difference of n and 8 is n − 8.
10 + 5 = n − 8
Answer: 10 + 5 = n − 8
Three times n is 3n.
The sum of that and 6 is 3n + 6.
3n + 6 = 27
Answer: 3n + 6 = 27
Twice n is 2n.
The sum of that and 11 is 2n + 11.
2n + 11 = 29
Answer: 2n + 11 = 29
Seven times n is 7n.
Decreased by 4 is 7n − 4.
7n − 4 = 38
Answer: 7n − 4 = 38
Twice n is 2n. Three times n is 3n.
Their sum is 2n + 3n.
5 added to that is 5 + (2n + 3n).
5 + (2n + 3n) = 35
Answer: 5 + (2n + 3n) = 35
3 times n is 3n.
8 less than that is 3n − 8.
3n − 8 = 19
Answer: 3n − 8 = 19
of means multiply.
35n = −9
Answer: 35n = −9
two tenths less than 3.5 is 3.5 − 210.
n = 3.5 − 210
Answer: n = 3.5 − 210
of means multiply.
410n = 1.6
Answer: 410n = 1.6
2 times n is 2n.
The difference of 2n and 13 is 2n − 13.
2n − 13 = 56
Answer: 2n − 13 = 56
The product of n and 1.5 is 1.5n.
1.5n = 6
Answer: 1.5n = 6
38 added to n is n + 38.
n + 38 = 2
Answer: n + 38 = 2
The product of 3.2 and 4.5 is 3.2 × 4.5.
n times 0.8 is 0.8n.
3.2 × 4.5 = 0.8n
Answer: 3.2 × 4.5 = 0.8n
Linear situations. The amount can increase or decrease at a constant rate.
Let h = the number of hours.
Let C = the total cost in dollars.
Start plus rate times hours.
C = 20 + 8h
Answer: C = 20 + 8h
Let h = the number of hours.
Let C = the total cost in dollars.
C = 9 + 4h
Answer: C = 9 + 4h
Let w = the number of weeks.
Let S = the amount in dollars.
S = 125 + 15w
Answer: S = 125 + 15w
Let t = the number of hours.
Let D = the total distance in miles.
D = 4 + 3t
Answer: D = 4 + 3t
Let m = the number of minutes.
Let A = the amount of water in gallons.
A = 80 + 6m
Answer: A = 80 + 6m
Let t = the number of minutes.
Let P = the total number of pages.
P = 25 + 12t
Answer: P = 25 + 12t
Let m = the number of miles.
Let C = the cost in dollars.
C = 2.75 + 0.90m
Answer: C = 2.75 + 0.90m
Let t = the number of minutes.
Let A = the amount of water in gallons.
A = 64 − 5t
Answer: A = 64 − 5t
Let h = the number of hours.
Let H = the height in inches.
H = 12 − 0.6h
Answer: H = 12 − 0.6h
Let d = the number of days.
Let B = the balance in dollars.
B = 420 − 24d
Answer: B = 420 − 24d
Let t = the number of minutes.
Let H = the height in feet.
H = 1800 − 60t
Answer: H = 1800 − 60t
Let t = the number of hours from the start.
Total cost = (cost of the first 4 hours) + (new rate)(hours after 4).
The first 4 hours cost $100. After that, the rate is $20 per hour.
t starts at the beginning, so the hours at $20 are t − 4.
100 + 20(t − 4) = 180
Answer: 100 + 20(t − 4) = 180
Let t = the number of hours from the start.
Total cost = (cost of the first 3 hours) + (new rate)(hours after 3).
The first 3 hours cost $18. After that, the rate is $6 per hour.
t starts at the beginning, so the hours at $6 are t − 3.
18 + 6(t − 3) = 54
Answer: 18 + 6(t − 3) = 54
Let t = the number of hours from the start.
Total cost = (cost of the first 2 hours) + (new rate)(hours after 2).
The first 2 hours cost $45. After that, the rate is $12 per hour.
t starts at the beginning, so the hours at $12 are t − 2.
45 + 12(t − 2) = 105
Answer: 45 + 12(t − 2) = 105
Let t = the number of hours from the start.
Total cost = (cost of the first 5 hours) + (new rate)(hours after 5).
The first 5 hours cost $80. After that, the rate is $25 per hour.
t starts at the beginning, so the hours at $25 are t − 5.
80 + 25(t − 5) = 230
Answer: 80 + 25(t − 5) = 230
Let t = the number of days from the start.
Total cost = (cost of the first 3 days) + (new rate)(days after 3).
The first 3 days cost $240. After that, the rate is $70 per day.
t starts at the beginning, so the days at $70 are t − 3.
240 + 70(t − 3) = 590
Answer: 240 + 70(t − 3) = 590
Write a simplified equation. Do not solve.
Let c = the number of croissants.
Blueberry muffins: 2c
Cinnamon rolls: c − 10
Croissants + blueberry muffins + cinnamon rolls = 85.
c + 2c + (c − 10) = 85
4c − 10 = 85
Answer: 4c − 10 = 85
Let r = the number of roses.
Tulips: 3r
Daisies: r − 8
Roses + tulips + daisies = 92.
r + 3r + (r − 8) = 92
5r − 8 = 92
Answer: 5r − 8 = 92
Let p = the number of palette knives.
8-inch is the length of each bamboo brush. The number of brushes is 3p.
4-inch is the length of each detailing pen. The number of pens is p + 5.
Palette knives + bamboo brushes + detailing pens = 40.
p + 3p + (p + 5) = 40
5p + 5 = 40
Answer: 5p + 5 = 40
Let n = the number of cones.
15-foot is the length of each agility ladder. The number of ladders is 2n.
6-inch is the height of each hurdle. The number of hurdles is n + 7.
Cones + agility ladders + hurdles = 43.
n + 2n + (n + 7) = 43
4n + 7 = 43
Answer: 4n + 7 = 43
Let g = the number of carabiners.
50-foot is the length of each rope. The number of ropes is 5g.
8-inch is the length of each stake. The number of stakes is g + 2.
Ropes + carabiners + stakes = 44.
g + 5g + (g + 2) = 44
7g + 2 = 44
Answer: 7g + 2 = 44
Let g = how many fewer garments to treat each week.
80 is the number of garments treated in a typical week. The equation uses the cost of one garment and the $6 savings.
One bottle costs $5 and treats 16 garments.
The cost of one garment is 516 dollars.
The cost of g fewer garments is the $6 the lab wants to save.
516g = 6
Answer: 516g = 6
Let v = how many fewer gallons of sap to boil each week.
90 is the number of gallons boiled in a typical week. The equation uses the cost of one gallon and the $5 savings.
One cord costs $7 and processes 20 gallons.
The cost of one gallon is 720 dollars.
The cost of v fewer gallons is the $5 the co-op wants to save.
720v = 5
Answer: 720v = 5
Let t = how many fewer meters of tubing to fill each week.
75 is the number of meters filled in a typical week. The equation uses the cost of one meter and the $4 savings.
One cylinder costs $5 and services 18 meters.
The cost of one meter is 518 dollars.
The cost of t fewer meters is the $4 the shop wants to save.
518t = 4
Answer: 518t = 4
Let w = how many fewer trays to load each week.
70 is the number of trays loaded in a typical week. The equation uses the cost of one tray and the $5 savings.
One bundle costs $3 and lasts for 14 trays.
The cost of one tray is 314 dollars.
The cost of w fewer trays is the $5 the bakery wants to save.
314w = 5
Answer: 314w = 5
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