The given system of equations is :
x−y=−11 ...(1)
y+7=−2x ...(2)
First step is to solve equation (1) for x so that we can substitute that x in equation (2) to get the value of y. So, add y to each sides of equation (1). Hence,
x = y - 11.
Next step is to plug in y - 11 for x in equation (2). So,
y + 7 = -2(y - 11)
y + 7 = -2y + 22 By distribution property.
y + 7 - 7 = -2y + 22 - 7 Subtract 22 from each sides.
y = -2y + 15
y + 2y = -2y + 15 + 2y Add 2y to each sides of the equation.
3y = 15
[tex] \frac{3y}{3} =\frac{15}{3} [/tex] Divide each sides by 3.
So, y = 5.
