To solve this system of equations, we can use the method of elimination.
First, multiply the first equation by 7 to make the coefficients of x in both equations cancel each other out when adding them together:
7(7x + 3y) = 7(-25)
49x + 21y = -175
Next, add this new equation to the second equation:
49x + 21y + -7x + 9y = -175 - 47
42x + 30y = -222
Now, we have a new equation:
42x + 30y = -222
Divide this equation by 6 to simplify it:
7x + 5y = -37
Now, we have two equations:
7x + 5y = -37
-7x + 9y = -47
Add the two equations together:
7x + 5y + -7x + 9y = -37 - 47
14y = -84
Divide by 14 to solve for y:
y = -6
Now that we have determined the value of y, we can substitute it back into one of the original equations to solve for x. Using the first equation:
7x + 3(-6) = -25
7x - 18 = -25
7x = -7
x = -1
Therefore, the solution to the system of equations is x = -1 and y = -6.
Solve the system of equations
7x + 3y = -25
-7x + 9y = -47
1 answer