solve using the substitution method.

-8x + y = 18

9x + 13y = 8

-8x + y = 18

9x + 13y = 8

y = 18 + 8x

9x + 13(18 + 8x) = 8

9x + 104x + 234 = 8

113x = -226

x = - 2

Now solve for y.

To solve this system of equations using the substitution method, follow these steps:

Step 1: Solve one of the equations for a variable in terms of the other variable.
Let's solve the first equation for y:
-8x + y = 18
y = 8x + 18

Step 2: Substitute the expression found in Step 1 into the other equation.
Substitute y = 8x + 18 into the second equation:
9x + 13(8x + 18) = 8

Step 3: Solve the resulting equation for the remaining variable.
Expand and simplify the equation:
9x + 104x + 234 = 8
113x + 234 = 8
113x = -226
x = -2

Step 4: Substitute the value of x back into one of the original equations to find the value of the other variable.
Let's substitute x = -2 into the first equation:
-8(-2) + y = 18
16 + y = 18
y = 2

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