Writing Equations
Write the following as an equation: eight more than four times a number is twenty-eight.
4n + 8 = 28
3x + 5 = 26
x = 7
3(x + 4) = 36
x = 8
-2s + 14 = 36
s = -11
Dylan bought 3 identical shirts online for a total cost of $71.83 including a flat rate of $7.99 for shipping. Write an equation to find the cost of each shirt, s.
3s + 7.99 = 71.83
2x - 4 = 20
x = 12
-4(x + 3) = 8
x = -5
Sylvie needs $110 for a concert ticket. She already has $16 and she can earn the rest by working 10 hours at her job. If h represents her hourly earnings, write an equation to represent Sylvie's hourly earnings.
10h + 16 = 110
Natalie paid $38.95 for three medium-sized pizzas and a salad. Write the equation that represents the cost of one pizza, p, if Natalie paid $11.98 for the salad.
50 + 6p = 335
p = 47.5
-5(s-30) = -10
s = 32
-2x + 1 = 7
x = -3
Write an equation that represents the situation: Miguel rode his bicycle 4 miles less than 5 times the number of miles that Nathan rode. Miguel rode his bicycle 6 miles, how many miles did Nathan ride?
1/2x + 6 = 16
x = 20
1/6(p + 24) = 10
p = 36
6(t + 12) = 114
t = 7
Five friends attend a movie and spend $8 per ticket. They also purchase a small bag of popcorn, p, each. If the friends spend a total of $62.50, write an equation that represents this situation.
5(8 + p) = 62.50
1 = x/6 - 10
x = 66
3 = 3/4b - 9
x = 16
Find the mistake :
–4(6 – b) = 4
–24 – 4b = 4
–4b = 28
b = –7
Negative times negative is a positive.
-4(-b) = 4b
b = 7