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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?

(, )

User Bikram
by
6.2k points

1 Answer

9 votes

Answer:

The solution to the system of equations is:


x = -9,
y=-3.4

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


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


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


x = -9

Therefore, the solution to the system of equations is:


x = -9,
y=-3.4

User Ponsiva
by
6.3k points