Subtract (4x − 3y) from the sum of (12x + 9y) and (−2y).

first step sum means addition so (12x+9y) +(-2y) = 12x +7y

second step subtract (4x -3y) from (12x+7y) 

need to use the distributive property:

12x +7y - 4x - -3y = 

12x + 7y - 4x +3y

 combine like terms

8x+10y

Answer has been edited.

Subtract (4x − 3y) from the sum of (12x + 9y) and (−2y) is 8x + 10y .

Step-by-step explanation:

As given the expression

(12x + 9y) , (-2y) and (4x − 3y) .

First add the expression (12x + 9y) and (-2y) .

= (12x + 9y) - (2y)

First open the bracket

= 12x + 9y - 2y

= 12x + 7y

Now subtracted (4x − 3y) from 12x + 7y .

=  12x + 7y - (4x - 3y)

= 12x - 4x + 7y + 3y

= 8x + 10y

Therefore the Subtract (4x − 3y) from the sum of (12x + 9y) and (−2y) is 8x + 10y .

x = -3

y = -18

step-by-step explanation:

to solve by substitution, substitute one variable and solve for the other. then substitute again to find the remaining variable.

x-1/3(3x-9) = -3 since y=3x-9 substittute y.

x-1/3(3x-9)=-3

x + x +3 = -3

2x+3=-3

2x+3-3= -3-3

2x=-6

x=-3

substitute again into y=3x-9

y=3(-3)-9

y=-9-9

y=-18