What is the question? if you are looking for the sides 2 sides are 40 and the other 2 are 20.
The rate a computer works is 1/time. Working together, you add the rates.
Let new computer be x, old computer be y.
x = y - 7

Rounded to nearest tenth gives:
x = 23 hours
Step-by-step explanation:

from difference of two squares:

therefore:

factorise out ¾ :

M=2,000÷((1−(1+0.072÷12)^(−12
×2))÷(0.072÷12))
M=89.73
Y = 1.25x + 30 <== ur function
for 3 hrs.....x = 3
y = 1.25(3) + 30
y = 3.75 + 30
y = 33.75 <=== for 3 hrs