Question

The solution to the system of equation below is (−2, −1).

2x − 3y = −1
11x − 9y = −13

When the first equation is multiplied by −3, the sum of the two equations is equivalent to 5x = −10.

Which system of equations will also have a solution of (−2, −1)?

A
5x = −10
11x − 9y = −13

B
2x + 9y = −1
11x − 9y = −13

C
−6x + 9y = −1
11x − 9y = −13

D
−6x + 3y = −1
5x = −10

Answer 1

Given:

4 system of equations:

5x = −10

11x − 9y = −13

2x + 9y = −1

11x − 9y = −13

−6x + 9y = −1

11x − 9y = −13

−6x + 3y = −1

5x = −10

To find:

Which system of equations will have a solution of (−2, −1)

Solution:

We will satisfy the point (-2,-1) in all the four equations and then check that which of the following equation has a solution of (-2,-1):

The first set of equations will have a solution of (-2,-1) as the point satisfies the set of equations.

5x = -10

5*(-2) = -10

-10 = -10

11x - 9y = -13

11*(-2) -9*(-1) = -13

-13 = -13

There the first set of equations i.e. option A has a solution (-2,-1).