Question

solve using substitution.
$x - 7y = 3$
$-x - 8y = 12$
$\left(\square, \square\
ight)$

Explanation:

Step1: Solve for x from first equation

From \( x - 7y = 3 \), we can express \( x \) as \( x = 7y + 3 \).

Step2: Substitute x into second equation

Substitute \( x = 7y + 3 \) into \( -x - 8y = 12 \). We get \( -(7y + 3) - 8y = 12 \).

Step3: Simplify and solve for y

Simplify the equation: \( -7y - 3 - 8y = 12 \), combine like terms: \( -15y - 3 = 12 \). Add 3 to both sides: \( -15y = 15 \), then divide by -15: \( y = -1 \).

Step4: Substitute y back to find x

Substitute \( y = -1 \) into \( x = 7y + 3 \), we get \( x = 7(-1) + 3 = -7 + 3 = -4 \).

Answer:

\((-4, -1)\)