Pre-lesson quiz : Algebraic Equations Part 1 (Grade 8)

1. Which of the following expressions represents this scenario:

Jill wants to buy magnets which cost R5 each. If y is her total cost, and x is the number of magnets which she can buy, then

• (a) x = 5y

• (b) y=5x

• (c) 5y=5x

2. You are given the following equation: y = 200x + 80. You are also told that this formula represents the following situation:

Peter has to pay R80 deposit to rent a popcorn machine, as well as R200 per day. If he pays the deposit and decides NOT to take the popcorn machine, he will NOT get the deposit back. What is the constant in the equation? (In other words, even if the number of days he rents the machine is “0”, what does he still have to pay?)

• (a) R200

• (b) R80

• (c) y

3. In the above question, what is the coefficient of x?

• (a) 80

• (b) 200

• (c) y

4. In the above example, what does the coefficient of x represent?

• (a) The total amount that he has to pay.

• (b) The daily rate of renting the popcorn machine.

• (c) The amount of the deposit.

5. What does the variable, x (the thing that can change) represent in the above example?

• (a) The number of days that he can rent the popcorn machine.

• (b) The deposit amount.

• (c) The total amount that he has to pay.

6. Calculate how much he will pay in total if he wants to rent the popcorn machine for 3 days.

• (a) R280

• (b) R680

• (c) R80

7. Solve the following algebraic expression, if x = 10, what is the value of y?

y = 7x + 8

• (a) y = 70

• (b) y = 78

• (c) y = 10

8. Is the following true or false: If 2a = 2, then a = 2.

• (a) True.

• (b) False.

9. A number raised to the power of 3 (x³) = 8. What is the number? (What is the value of x?)

• (a) 3

• (b) 2

• (c) 4

10. Fifteen times a number is 90. What is the number?

• (a) 10

• (b) 6

• (c) 5