Answer:
x = -1
y = 5
Step-by-step explanation:
x+y=4
3x+7y=32
To solve a pair of equations using substitution, first solve one of the equations for one of the variables. Then substitute the result for that variable in the other equation.
x+y=4,3x+7y=32
Choose one of the equations and solve it for x by isolating x on the left hand side of the equal sign.
x+y=4
Subtract y from both sides of the equation.
x=−y+4
Substitute −y+4 for x in the other equation, 3x+7y=32.
3(−y+4)+7y=32
Multiply 3 times −y+4.
−3y+12+7y=32
Add −3y to 7y.
4y+12=32
Subtract 12 from both sides of the equation.
4y=20
Divide both sides by 4.
y=5
Substitute 5 for y in x=−y+4. Because the resulting equation contains only one variable, you can solve for x directly.
x=−5+4
Add 4 to −5.
x=−1
