Solve using substitution.

7x − 9y = –5
x = 7

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1 answer

To solve the system of equations using substitution, we first substitute the value of \( x \) from the second equation into the first equation.

Given:

  1. \( 7x - 9y = -5 \)
  2. \( x = 7 \)

Now, substitute \( x = 7 \) into the first equation:

\[ 7(7) - 9y = -5 \]

Calculating \( 7(7) \):

\[ 49 - 9y = -5 \]

Next, we need to isolate \( y \). Start by subtracting 49 from both sides:

\[ -9y = -5 - 49 \]

This simplifies to:

\[ -9y = -54 \]

Now, divide both sides by -9:

\[ y = \frac{-54}{-9} = 6 \]

So, we have found \( y = 6 \) and \( x = 7 \).

The solution in coordinate form is:

\[ (7, 6) \]