SOLUTION: i have always been taught the order of operations as PEMDAS p-parenthesis e-exponent m-multiply d-divide a-add s- subtract, but when it comes to combining like terms in long equat

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Question 729983: i have always been taught the order of operations as PEMDAS p-parenthesis
e-exponent m-multiply d-divide a-add s- subtract, but when it comes to combining like terms in long equations that involve the order of operations, i get confused. can you explain an easier way to help me do equations like this:
-7(8y+9)-8y(7+-5) (i guess this can also be taken as an expression too.)
Found 2 solutions by rfer, josgarithmetic:
Answer by rfer(16322) About Me  (Show Source):
You can put this solution on YOUR website!
-7(8y+9)-8y(7-5)
-56y-63-8y(2)
-56y-63-16y=
-72y-63

Answer by josgarithmetic(39838) About Me  (Show Source):
You can put this solution on YOUR website!
-7%288y%2B9%29-8y%287%2B-5%29


Parentheses.
-7%288y%2B9%29-8y%282%29


Multiplications.
-56y-63-16y


Do NOT ignore other number properties. So far the expression is now equivalent to -56y+%2B+-63+%2B+-16y.
Commutative Property of Addition.
-56y+%2B+-16y+%2B+-63


Additions.
-72y+%2B+-63
Note that was "combining like-terms".

Possible finishing simplification,
-72y-63.

Notice that some operations were not really included. Rendering all addition or subtractions into only additions was convenient for me but not always what each person wants. My method only relied for your example, on P, M, and A from your PEMDAS mnemonic.