Solve.

7x + 10y = 10
–3x − 2y = 14

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1 answer

To solve the system of equations given by

  1. \( 7x + 10y = 10 \)
  2. \( -3x - 2y = 14 \)

we can use either the substitution method or the elimination method. Here, I'll use the elimination method.

Let's first rewrite the second equation in a more convenient form:

\[ 3x + 2y = -14 \]

Now we have the two equations:

  1. \( 7x + 10y = 10 \)
  2. \( 3x + 2y = -14 \)

Next, we can eliminate one of the variables. To eliminate \( y \), we can make the coefficients of \( y \) in both equations the same. We can multiply the second equation by 5 to get the coefficient of \( y \) to match that in the first equation:

Multiply the second equation by 5:

\[ 5(3x + 2y) = 5(-14) \implies 15x + 10y = -70 \]

Now our equations are:

  1. \( 7x + 10y = 10 \)
  2. \( 15x + 10y = -70 \)

Next, we'll subtract the first equation from the second to eliminate \( y \):

\[ (15x + 10y) - (7x + 10y) = -70 - 10 \]

This simplifies to:

\[ 15x - 7x = -80 \implies 8x = -80 \]

Now we solve for \( x \):

\[ x = \frac{-80}{8} = -10 \]

Now that we have \( x \), we can substitute it back into one of the original equations to find \( y \). We can use the first equation:

\[ 7(-10) + 10y = 10 \]

This simplifies to:

\[ -70 + 10y = 10 \]

Now solve for \( y \):

\[ 10y = 10 + 70 \implies 10y = 80 \implies y = \frac{80}{10} = 8 \]

Thus, the solution to the system of equations is:

\[ (x, y) = (-10, 8) \]

The final answer is:

\[ \boxed{(-10, 8)} \]