## Equations Exercise

1. This question is called "Find the number" Find the missing number in each of the following questions:

a. A number has 5 added to it and the result is 15. Find the number.

b. 12 is subtracted from a number and the result is 5. Find the number.

c. A number is multiplied by 3 and the result is 36. Find the number.

d. When a number is divided by 12 the result is 10. Find the number.

e. A number plus 8 is equal to 22, find the number.

f. When a number is doubled and 6 is added then the answer is 2. Find the number.

g. A number is divided by 3 and then 6 is taken away. The result is 27. Find the number.

h. A number has 3 added to it and the result is multiplied by 2. The answer is 22. Find the number.

2. Solve the following equations. Remember to check your solution by substituting back into the original equation.

 a a + 4 = 15 b 6b = 48 c c + 6 = 10 d d ÷ 5 = 30 e e − 3 = 12 f 2 + f = 3 g g + 7 = 14 h h − 9 = 20 i 7i = 42 j j ÷ 3 = 33 k k − 5 = 43 l l + 5.5 = 12 m m + 6.5 = 12.5 n 8n = 20

3. Solve the following equations. These ones are a bit harder!

Remember to check your solution by substituting back into the original equation.

 a 20 − a = 12 b 43 − b = 30 c c + 6 = -10 d -2d = 14 e e − 20 = -12 f 2 = 3 + f g 2g + 5 = 15 h 2h − 2 = 48 i 3i + 7 = 19 j 5j + 6 = 26

4. For the following word problems, write an equation using the variable given and then solve it to find the answer to the problem.

 a. A restaurant buys trout and freshwater crayfish for \$300. The trout cost a total of \$175. What is the cost of the freshwater crayfish? (Let the cost of the freshwater crayfish be f.) b. A CD and a DVD cost me \$60 in total. If the CD costs \$25, what is the cost of the DVD? (Let the cost of the DVD be v.) c. An ice cream and a drink cost \$7. If the drink costs \$4.50, what is the cost of the ice cream?(Let the cost of the ice cream be c.) d. The ages of a boy and his sister add up to 28. If the boy is 12, how old is his sister?(Let the age of the sister be s.) e. A family buy a car and a motorcycle for a total of \$5200. The motortcycle costs \$1250. What is the cost of the car?(Let the cost of the car be c.) f. I buy a pie, a sandwich and a drink for \$9.40. The pie costs \$3.50 and the sandwich costs \$3.10. What is the cost of the drink?(Let the cost of the car be d.) g. I buy 3 tennis rackets and a squash racket for \$250. The squash racket costs \$70. How much does each squash racket cost?(Let the cost of each tennis racket be t.) h. A supermarket company buys 3000 light bulbs so that each store gets 600 light bulbs. How many stores does the supermarket company have?(Let the number of the stores be s.)