Question

With steps... Thanks..

Answer 1

a. -25x - y

b. pq ( - p + 5q )

Explanation:

a.

`- 15x + 6y - (10x + 7y)`

When there is a (-) in front of an expression in parentheses, change the sign of each term in the expression

`- 15x + 6y - 10x - 7y`

Collect like terms

`- 15x - 10x + 6y - 7y`

`- 25x - y`

b.

`2pq(p + q) - 3pq(p - q)`

Factor out pq from the expression

`pq(2(p + q) - 3(p - q))`

Distribute 2 through the parentheses

`pq \: (2p + 2q - 3(p - q)`

Distribute -3 through the parentheses

`pq \: (2p + 2q - 3p + 3q)`

Collect like terms

`pq( - p + 5q)`

Hope this helps...

Best regards!!

Answer 2

`\boxed{-25x-y}`

`\boxed{-p^2q +5pq^2}`

Explanation:

`(-15x+6y)-(10x+7y)`

Distribute negative sign.

`-15x+6y-10x-7x`

Combine like terms.

`\boxed{-25x-y}`

`2pq(p+q)- (3pq(p-q))`

Expand brackets.

`2p^2 q+2pq^2 -(3p^2q-3pq^2)`

Distribute negative sign.

`-3p^2q+3pq^2+2p^2q+2pq^2`

Combine like terms.

`\boxed{-p^2q +5pq^2}`