Question

question 3
solve the following system of equations with the substitution method:
{3x + y = -2
{-3x + 3y = -18
answer: (□,□)
enter your answers as integers or as reduced fractions in the form a/b.

Explanation:

Step1: Isolate y in the first - equation

From $3x + y=-2$, we get $y=-2 - 3x$.

Step2: Substitute y into the second equation

Substitute $y=-2 - 3x$ into $-3x + 3y=-18$. Then $-3x+3(-2 - 3x)=-18$.
Expand the left - hand side: $-3x-6 - 9x=-18$.
Combine like terms: $-12x-6=-18$.
Add 6 to both sides: $-12x=-18 + 6=-12$.
Divide both sides by - 12: $x = 1$.

Step3: Find the value of y

Substitute $x = 1$ into $y=-2 - 3x$. Then $y=-2-3\times1=-2 - 3=-5$.

Answer:

$(1,-5)$