System of Equations:
- Equation 1: \( 7x + 6y = 10 \)
- Equation 2: \( 3x + 5y = -3 \)
Method: We will use the elimination method. To do this, we'll multiply the first equation by 3 and the second equation by 7 to make the coefficients of x opposites.
Step-by-step solution:
- Step 1: Multiply Equation 1 by 3 and Equation 2 by 7
Multiply Equation 1 by 3: \( 3(7x + 6y) = 3(10) \) which gives \( 21x + 18y = 30 \).
Multiply Equation 2 by 7: \( 7(3x + 5y) = 7(-3) \) which gives \( 21x + 35y = -21 \). - Step 2: Subtract the modified Equation 2 from the modified Equation 1
Subtract the second modified equation from the first modified equation:
\( (21x + 18y) - (21x + 35y) = 30 - (-21) \)
\( 21x + 18y - 21x - 35y = 30 + 21 \)
\( -17y = 51 \) - Step 3: Solve for y
Divide by -17: \( y = 51 / -17 \)
\( y = -3 \) - Step 4: Substitute y back into Equation 1 to find x
Substitute \( y = -3 \) into the original Equation 1: \( 7x + 6y = 10 \)
\( 7x + 6(-3) = 10 \)
\( 7x - 18 = 10 \) - Step 5: Solve for x
Add 18 to both sides: \( 7x = 10 + 18 \)
\( 7x = 28 \)
Divide by 7: \( x = 4 \)
Answer: x = 4, y = -3