Question

Use the elimination method to solve the system of equations.
2x + 3y = 8
x - y = 9

Answer 1

Okay you have isolate a variable. As long as you perform the some operation on both sides the equations holds true. So I'll multiply the bottom one by three. 3x - 3y = 27. Now if I add the equations together I get 5x is 35 or x is 7. Then plug it back into either equation. 7 minus what is 9? -2. Y is -2

Answer 2

Answer: x = 7 and y = -2

Explanation:

2x +3y = 8 ----------------(1)

x-y = 9 ----------------------(2)

multiply (2) by 2

2x-2y = 18--------------------(3)

subtract (2) from (3)

-5y = 10

Divide bothside by -5

y = -2

Similarly, multiply (2) by 3

3x-3y = 27-----------------------(4)

add (1) and (4) together

5x = 35

Divide bothside by 5

x= 7

Therefore, x =7 and y= -2