6x−10y=730
7x-9=y
Solve the system by substitution.
substitute 7x-9 for y ... 6x - 10 (7x - 9) = 730
... 6x - 70x + 90 = 730
solve for x , then substitute back to find y
6x−10y=730
7x-9=y
Solve the system by substitution
To solve the system of equations using substitution, we will solve one of the equations for one variable and then substitute that expression into the other equation.
Let's start by solving the second equation for y:
7x - 9 = y
Now, substitute this expression for y in the first equation:
6x - 10y = 730
6x - 10(7x - 9) = 730
Distribute the -10:
6x - 70x + 90 = 730
Combine like terms:
-64x + 90 = 730
Subtract 90 from both sides:
-64x = 640
Now, divide by -64 on both sides to isolate x:
x = 640 / -64
x = -10
Now, substitute this value of x back into the second equation to solve for y:
7(-10) - 9 = y
-70 - 9 = y
y = -79
Therefore, the solution to the system of equations is x = -10 and y = -79.