Question 61390
Solve the system by substitution.	
E1:  3x+3y=6	          
E2:  y=–4x–10
:
Substitute -4x-10 in for y in E1 and solve for x.
3x+3(-4x-10)=6
3x-12x-30=6
-9x-30=6
-9x-30+30=30+6
-9x=36
{{{-9x/-9=36/-9}}}
x=-4
Substitute -4 in for x in E2 and solve for y.
y=-4(-4)-10
y=16-10
y=6
The solution (x,y)=(-4,6)
:
Check the solution in both equations.
3(-4)+3(6)=6
-12+18=6
6=6  The solution checks in E1.
:
6=-4(-4)-10
6=16-10
6=6 The solution checks in E2.
We're right!!!
Happy Calculating!!!