Question

Solve using substitution.

4x − 10y = 18
y = –5

Answer 1

To solve the system of equations using substitution, we start with the given equations:

1. \( 4x - 10y = 18 \)
2. \( y = -5 \)

Since \( y \) is already expressed in terms of a constant, we can substitute \(-5\) for \(y\) in the first equation.

Substituting \( y = -5 \) into the first equation:

\[
4x - 10(-5) = 18
\]

Now simplify the equation:

\[
4x + 50 = 18
\]

Next, isolate \(4x\) by subtracting \(50\) from both sides:

\[
4x = 18 - 50
\]

\[
4x = -32
\]

Now, divide both sides by \(4\) to solve for \(x\):

\[
x = \frac{-32}{4}
\]

\[
x = -8
\]

Now we have the solution for the system of equations:

\[
x = -8, \quad y = -5
\]

Therefore, the solution is \( (x, y) = (-8, -5) \).