Multiple Choice Question (MCQ)
What is the solution (x,y) to the system of equations below?
\begin{alignedat}{2} 3 &x+ &4 &y = -23 \\ 2 & y- & &x = -19 \end{alignedat}
-
×
(-5,-2)
-
✓
(3,-8)
-
×
(3,-6)
-
×
(9,-6)
What is the solution (x,y) to the system of equations below?
\begin{alignedat}{2} 3 &x+ &4 &y = -23 \\ 2 & y- & &x = -19 \end{alignedat}
(-5,-2)
(3,-8)
(3,-6)
(9,-6)
\begin{alignedat}{2} 3 &x+ &4 &y = -23 \\ 2 & y- & &x = -19 \end{alignedat}
Multiplying both sides of 2nd equation by 3 gives
\begin{alignedat}{2} 3 &x+ &4 &y = -23 \\ 6 & y- & 3&x = -57 \end{alignedat}
Addition of the two equations to cancel term with x
10y = -80
y=-8
Back substitution yields
x = 3
B is correct choice