Answer:
9 hours
Step-by-step explanation:
Set up the equations: x is the amount of hours Amber worked and y is the hours Jake worked
8x + 8y = 120
y = 3 + x
Substitute the second equation into the first
8x + 8(3+x) = 120
Distribute
8x + 24 + 8x = 120
Combine like-terms
16x + 24 = 120
Subtract 24 on both sides
16x = 96
Divide 16 on both sides
x = 6 (hours Amber worked)
Plug in this x-value into on of the two equations. I will use the second
y = 3 + 6
y = 9
Add all the sides together
7.2+14.8+16.1+18 = 56.1
_________X=30____
_________-________
So, the sphere went from 1.2 meters to 1.4 meters.
The radius will always be half of the diameter. So it went from .6 to .7.
Let's divide and see what percent .7 is of .6.
.7÷.6=1.166666666(repeating 6).
This means, it increased by about 16.7%, since it was not doubling, just going up.
7.87 is what i got :) good luck!!