Solve the system by substitution.

Question

minus, 4, x, minus, y, equals, 1
−4x−y=
1
minus, 9, x, plus, 9, equals, y
−9x+9=
y

Answer 1

To solve the system by substitution, we need to solve one equation for one variable and substitute that expression into the other equation.

Let's start by solving the second equation, "-9x + 9 = y," for y:
y = -9x + 9

Now we substitute this expression for y in the first equation, "-4x - y = 1":
-4x - (-9x + 9) = 1
-4x + 9x - 9 = 1
5x - 9 = 1

Adding 9 to both sides of the equation:
5x = 1 + 9
5x = 10

Dividing both sides of the equation by 5:
x = 10/5
x = 2

Now that we have found the value of x, we can substitute it back into the second equation to find y:
y = -9(2) + 9
y = -18 + 9
y = -9

Therefore, the solution to the system of equations is x = 2 and y = -9.