Question

Solve the system of equations 9x - 9y = -9 and 4x - 3y = -8 by combining the equations.

a) x = 2, y = 1
b) x = 1, y = 2
c) x = -2, y = -1
d) x = -1, y = -2

Answer 1

To solve the system of equations 9x - 9y = -9 and 4x - 3y = -8, we can use the combination method. The solution to the system of equations is x = -5 and y = -4.

Step-by-step explanation:

To solve the system of equations 9x - 9y = -9 and 4x - 3y = -8, we can use the method of elimination or combination. Here, we'll use the combination method.

Multiply the first equation by 3 and the second equation by 9 to eliminate the y term:

27x - 27y = -27

36x - 27y = -72

Subtract the second equation from the first equation:

(27x - 27y) - (36x - 27y) = -27 - (-72)

-9x = 45

Divide both sides by -9:

x = -5

Substitute this value of x into one of the equations:

9(-5) - 9y = -9

-45 - 9y = -9

Add 45 to both sides:

-9y = 36

Divide both sides by -9:

y = -4

Therefore, the solution to the system of equations is x = -5 and y = -4.