Question

Which of the following ordered pairs represents the solution to the system of equations below?

-3x+2y=2
7x-3y=7

A. (2, 4)
B. (4, 7)
C. (7, 14)
D. (8, 13)

Answer 1

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

7x - 3y = 7 eq (2)

Mutiply eq (1) by 3 and eq (2) by 2:

-9x + 6y = 6

14x - 6y = 14

Add th two new equations:

-9x + 14x = 6 + 14

=> 5x = 20

=> x = 20/5

=> x = 4

Now from eq (1)

-3(4) + 2y = 2

=> 2y = 2 + 12

=> 2y = 14

=> y = 14 / 2

=> y = 7

So the ordered pair is (4,7)

Answer: option B. (4,7)