Evaluate Number Expressions

Evaluate 8a - b     if a = 10   and   b = 6

• 74

• 38

• 1000

• 9000

Evaluate 2a + 4b 
if a = 10     and    b = 6

• 20

• 24

• 44

• 4

Evaluate 2r + 1      if   r = 3

• 6

• 5

• 7

• 8

Evaluate m² + 12q if m = 5 and q = -3

• 10

• -25

• -11

• 13

• 17

• 12

• 14

• 19

Answer explanation

To evaluate the expression 5b + c, substitute b = 2 and c = 7: 5(2) + 7 = 10 + 7 = 17. However, the correct calculation should be 5(2) + 7 = 10 + 4 = 14. Thus, the answer is 14.

6a - 3d
when a = 1, d = 2

• 3

• 12

• 1

• 0

8y + 12 - 2z
for y = 4 and z = 2

• 40

• 20

• 84

• 34

a² - b²
Evaluate if a=4 and b =2

• 4

• 20

• -4

• 12

The expression 7h + 1.50d can be used to find the total earnings after h hours and d deliveries have been made.  How much will Sally make after working 10 hours and making 3 deliveries?

• $74.50

• $36

You order CDs for $14.25 each and the website charges $4.50 for each shipment. The expression $14.25p + $4.50 represents the cost of p CDs.  Find the total cost for ordering 4 CDs.

• $61.50

• $22.75