Answer:
8+7x+4y
Explanation:
15+12x-5x+4y-7
15, and -7 are like terms. 12x, and -5x are like terms. 4y does not have a like term.
So we substract 7 from 15 and that equals 8.
Then we substract 5x from 12x and that equals 7x.
And we leave the 4y alone.
Hope this help you.