Question

please hurry I need to get this done HURRY!!!!!!!


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

Answer:

The solution to the system of equations is:

$x = -9$,   $y=-3.4$

Step-by-step explanation:

Given the system of equations

-2.1x + 4y = 5.3

2.1x - 5.5y = -0.2

Solving the system of equations using the linear combination method

$\begin{bmatrix}-2.1x+4y=5.3\\ 2.1x-5.5y=-0.2\end{bmatrix}$

adding the equations

$2.1x-5.5y=-0.2$

$+$

$\underline{-2.1x+4y=5.3}$

$-1.5y=5.1$

solving -1.5y = 5.1 for y

$-1.5y=5.1$

Divide both sides by -1.5

$\frac{-1.5y}{-1.5}=\frac{5.1}{-1.5}$

$y=-3.4$

substitute y = -3.4 in 2.1x - 5.5y = -0.2

2.1x - 5.5y = -0.2

2.1x - 5.5(-3.4) = -0.2

2.1x + 18.7 = -0.2

2.1x = -0.2-18.7

2.1x = -18.9

Divide both sides by 2.1

$\:\frac{2.1x}{2.1x}\:\:=\:\:\frac{-18.9}{2.1}$

$x = -9$

Therefore, the solution to the system of equations is:

$x = -9$,   $y=-3.4$