Answer:
x=4 and y=5 commonly notated as (4,5)
Step-by-step explanation:
The equations
Equation 1: 3x+3y=27
Equation 2: x-3y= -11
The second equation looks like it will be the easiest to rearrange.
x-3y = -11
add 3y to each side to get
x = 3y-11
Substitute that in for x in equation 1 so
3x+3y=27
turns into
3(3y-11) +3y =27
multiply out to get
9y-33+3y =27
Condense variables
12y-33=27
add 33 to each side
12y= 60
Divide by 12
y = 5
Plug into one of the original equations (I will be doing both to show it doesn't matter what equation you use, but you only need to use one equation, I personally think it is easier to plug into the second equation)
Equation 1: 3x+3y=27
Plug in what we got for y
3x+3(5)=27
multiply
3x+15=27
subtract 15 from each side
3x=12
divide by 3
x=4
Equation 2: x-3y = -11
Plug in what we got for y
x-3(5) =-11
Multiply
x-15= -11
Add 15 to each side
x=4
