Solving Equations Using Substitution Quick Check
2 of 52 of 5 Items


Question
Solve the system of equations.
2x+6y=−18

x=5y−1
(1 point)
Responses

(4, 1)
left parenthesis 4 comma 1 right parenthesis

(5.25, 1.25)
left parenthesis 5.25 comma 1.25 right parenthesis

(−7.25, −1.25)
left parenthesis negative 7.25 comma negative 1.25 right parenthesis

(−6, −1)

Answers

Answered by GPT-4o mini
To solve the system of equations using substitution, we have the following equations:

1. \(2x + 6y = -18\) (Equation 1)
2. \(x = 5y - 1\) (Equation 2)

We can substitute Equation 2 (the expression for \(x\)) into Equation 1.

Substituting \(x = 5y - 1\) into Equation 1:

\[
2(5y - 1) + 6y = -18
\]

Now, distribute the 2:

\[
10y - 2 + 6y = -18
\]

Combining like terms:

\[
16y - 2 = -18
\]

Now, add 2 to both sides:

\[
16y = -16
\]

Divide by 16:

\[
y = -1
\]

Now that we have \(y\), we can substitute it back into Equation 2 to find \(x\):

\[
x = 5(-1) - 1
\]
\[
x = -5 - 1
\]
\[
x = -6
\]

Thus, the solution to the system of equations is \((-6, -1)\).

Comparing this with the given options, the correct response is:

**(−6, −1)**

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