Writing and Solving Equations

Addition Equations

100

x + 4 = 7

x = 3

200

15 = b + 4

b = 11

300

a + 2.3 = 5.72

a = 3.42

400

5/7 = y + 3/7

y = 2/7

500

3/4 = c + 1/3

c = 5/12

Subtraction Equations

100

x - 5 = 14

x = 19

200

6 = d - 4

d = 10

300

t - 0.87 = 4.2

t = 5.07

400

x - 5/8 = 1/2

x = 9/8 or 1 1/8

500

3/7 = a - 3/5

a = 36/35 or 1 1/35

Multiplication Equations

100

2b = 14

b = 7

200

8x = 72

x = 9

300

13 = 2.5a

a = 5.2

400

2/3b = 6

b = 9

500

4.2t = 29.4

t = 7

Division Equations

100

2 = x/16

x = 32

200

x/3 = 4

x = 12

300

22 = y/3

y = 66

400

m/5 = 8/15

m = 8/3 or 2 2/3

500

k/2.6 = 2.1

k = 5.46

Write and Solve Equations

100

WRITE AN EQUATION & SOLVE: Julie is 3 years older than her sister. Julie's age is 11 years old. How old is her sister?

n - Julie's sister's age n + 3 = 11 n = 8 Julie's sister is 8 years old.

200

Mr. Cushman bought 7 Hannah Montana t-shirts for a total of $90.93. Each t-shirt cost the same amount. How much did each t-shirt cost?

n - cost of t-shirts 7n = 90.93 n = 12.99 Each t-shirt cost $12.99

300

Tyler goes to his friends house. It takes him 42 minutes to get there by walking. This is 6 times the time it takes by car. How long does it take Tyler to get there by car?

c - time it takes to get there by car 42 = 6c c = 7 It takes 7 minutes by car.

400

Larry is buying a ham. He wants to divide it into 6.5-ounce servings for 12 people. Write and solve an equation to find what size ham Larry should buy.

h - size of ham Larry should buy h/6.5 = 12 or h/12 = 6.5 h = 78 He should buy a 78-ounce ham

500

Carl studied for science 1/5 of an hour, math for 1/3 of an hour and language arts for 1/4 of an hour. Write and solve an equation to find how much time he has left in the hour for video games.

t = time left for video games 1/5 + 1/3 + 1/4 + t = 1 47/60 + t = 1 t = 13/60 Carl will have 13 minutes to play video games.