Respuesta :

Answer:  x-3y+12

Step-by-step explanation:

You need to know the rules for signed numbers.  Study them.

Assuming addition of integers:

Separate your like terms and simply them:

so starting with x terms: -3x+4x ; (4x is the same as saying +4x)

so next with y terms: -2y-y; (remember -y is the same as saying -1y)

so next number with no terms: +7+5

Solve for each:  -3x+4x= 1x

                          -2y-y= -3y

                           +7+5= 12

Simplify expression with solved termsin order:  1x-3y+12

ans: x -3y +12

Hope this helped.