Solve the system of equations 3x- 4y = 40 and 5x- 5y = 55. A. (4, -7) b. (14, 3) c. (8, -3) d. (18, 7)

Answer 1

To solve this system of equations, we can use the method of substitution.

First, we solve one equation for one variable in terms of the other variable. Let's solve the second equation for x:

5x - 5y = 55
5x = 5y + 55
x = (5y + 55)/5
x = y + 11

Now we substitute this expression for x into the first equation:

3x - 4y = 40
3(y + 11) - 4y = 40
3y + 33 - 4y = 40
-y + 33 = 40
-y = 40 - 33
-y = 7
y = -7

Using this value of y, we can substitute it back into the expression for x:

x = y + 11
x = -7 + 11
x = 4

Therefore, the solution to the system of equations is (4, -7).