Answer:
He did 9 times 10 instead of 9 times 100.
Check out the picture I've got the full explanations on there
Hope it's clear
Step-by-step explanation:
2y+9= 4
2y=-5
y=-5/2
y= -2and 1/2
There are 5280 feet in a mile. So divide 607,200 feet by 5280 to get 115. The go-kart's speed is 115 miles per hour.