17)
Find how many more pencils are needed:
250 - 108 = 142
Divide by the number of pencils in a box:
142 / 16 = 8.875 = 9 more boxes.
18) 5/4x - 3(8x-1/4)
Use the distributive property:
5/4x - 24x - 3/4
Rewrite 24x as 96/4x
Now you have:
5/4x - 96/4x-3/4
Combine like terms:
-91/4x - 3/4
19)
Car: 3 feet in 4 seconds
60 seconds / 4 = 15
3 feet x 15 = 45 feet per minute
Truck: 2 feet in 6 seconds
60 seconds / 6 = 10
2 feet x 10 = 20 feet per minute
45 - 20 = 25 feet
The car travels 25 feet per minute faster.
