To solve this we must set up a proportion.
For each pie we need 2 pounds because you divide 4 by 2.
So we do 5 times 2 which gives us 10 pounds per 5 pies
Your answer is
You need 10 pounds of apples for 5 pies.
A = l * w. w = x; l = 5 + 2x
(5+2x)x=900
I don't know if you still need help with this, but the answer is exact interest and he saves $1.34.
If you put brackets around (2+1), your method of working is:
1) 15-4*(2+1)=3
2) 15-4*3=3
3) 15-12=3
You don't need any more brackets, as the BIDMAS (brackets, Indices, division, multiplication, addition, subtraction) rule does the rest of the job for you.
The answer is therefore: 15-4*(2+1)=3
