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?

(Point on a graph)

Answer 1

y=-3.34 x=-8.89

Combine two equations

0x-1.5y=5.01

-1.5y/-1.5=5.01/-1.5

y=-3.34

Plug in the y value for in one of the equations to solve for x.

-2.1x + 4(-3.34) = 5.3

-2.1x -13.36= 5.3

-2.1x = 18.66

-2.1x/-2.1 = 18.66/-2.1

x=-8.89

Plug in both values to validate the answer. Keep in mind there was rounding so the equation will not 100% be correct.

2.1(-8.89) - 5.5(-3.34) =

-18.66 + 18.37 = -0.29

-2.1(-8.89) + 4(-3.34) = 5.309

Answer 2

Figures

figure 2.1

Figure 2.1

figure 2.10

Figure 2.10

figure 2.12

Figure 2.12

figure 2.13

Figure 2.13

Explanation: