Question

9.


A. (3, 6)

B. (20, –4)

C. (10, –1)

D. (–1, 8)

Answer 1

(10, –1)

Explanation:

[1]XXXX3y=−12x+2

[2]XXXXy=−x+9

While it is not technically necessary, I find it easier to clear the fractions before actually beginning; so multiplying [1] by 2

[3]XXXX6y=−x+4

Substituting (from [2]) (−x+9) for y in [3]

[4]XXXX6(−x+9)=−x+4

Simplifying

[5]XXXX−6x+54=−x+4

[6]XXXX5x=50

[7]XXXXx=10

Substituting (from [7]) 10 for x in [2]

[8]XXXXy=−10+9=−1