question\nfind the solution of the system of equations.\n-3x + 9y = -21\n-3x + 8y = -18
question\nfind the solution of the system of equations.\n-3x + 9y = -21\n-3x + 8y = -18
Answer
Explanation:
Step1: Subtract the second equation from the first
$$ \begin{align*} (-3x + 9y)-(-3x + 8y)&=-21-(-18)\ -3x + 9y + 3x-8y&=-21 + 18\ y&=-3 \end{align*} $$
Step2: Substitute (y = - 3) into the second equation
Substitute (y=-3) into (-3x + 8y=-18), we get (-3x+8\times(-3)=-18). Simplify: (-3x-24=-18). Add (24) to both sides: (-3x=-18 + 24), so (-3x = 6). Divide both sides by (-3): (x=-2).
Answer:
(x=-2,y = - 3)