To solve this system of equations, we can use the method of substitution or elimination. Let's use the elimination method.
First, we will multiply the first equation by 5 and the second equation by 4 to eliminate y:
15x - 20y = 200
20x - 20y = 220
Now we subtract the second equation from the first equation:
15x - 20x - 20y + 20y = 200 - 220
-5x = -20
x = 4
Now that we have found the value of x, we can substitute it back into one of the original equations to solve for y. Let's use the first equation:
3(4) - 4y = 40
12 - 4y = 40
-4y = 28
y = -7
Therefore, the solution to the system of equations is x = 4 and y = -7. So, the answer is B. (4,-7).
Solve the system of equations.
3x - 4y = 40
5x - 5y = 55
A. (8,-3)
B. (4,-7)
C. (18, 7)
D. (14, 3)
1 answer