Hi there!
2³ [ (15 - 7) × (4 ÷ 2) ] = 8 [ 8 × 2 ] = 8 × 16 = 128
Hence,
The required answer is 128
~ Hope it helps!
In order to answer the question, it's absolutely essential to have
enough of a description of the object to know which of its parts
'X', 'Y', and 'Z' are, and what other parts it may have.
An ideal way to accomplish this would have been for you to include the
picture that accompanies the question, wherever you copied it from.
If we let 
be the number of pages read in 1 hour, then in 7 hours Doug reads 
pages. We know that this number of pages is 231, so we have
To write the equation you start with the 125 because it is monthly and it doesn't say how often you pay the 75 dollars so the equation would be c(f)=125x+75
