Question

Use the linear combination method to solve the system of equations. –2.1x + 4y = 5.3 2.1x – 5.5y = –0.2 What is the solution to the system? ( , )

Answer 1

(-9, -3.4)

Explanation:

-2.1x + 4y =5.3

2.1x - 5.5y = -0.2

Add both equations (cancelling x variable).

0 + -1.5y = 5.1

Solve for y.

-1.5y = 5.1

(-1.5y)/-1.5 = 5.1/-1.5

y = -3.4

Plug y as -3.4 in the first equation.

-2.1x + 4(-3.4) = 5.3

Solve for x.

-2.1x + -13.6 = 5.3

-2.1x - 13.6 + 13.6 = 5.3 + 13.6

-2.1x = 18.9

(-2.1x)/-2.1 = 18.9/-2.1

x = -9

Answer 2

Answer: (-9, -3.4)

x = -9

y = -3.4

Explanation:

-2.1x+4y=5.3

2.1x-5.5y=-0.2

0-1.5y=5.1

-1.5y=5.1

y=-3.4

Then plug in -3.4 for y in the first equation to get x = -9

Hope it helps <3