Answer:
vz
Explanation:
3x+y=−5,x=y−3
Consider the second equation. Subtract y from both sides.
x−y=−3
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.
3x+y=−5,x−y=−3
Choose one of the equations and solve it for x by isolating x on the left hand side of the equal sign.
3x+y=−5
Subtract y from both sides of the equation.
3x=−y−5
Divide both sides by 3.
x=
3
1
(−y−5)
Multiply
3
1
times −y−5.
x=−
3
1
y−
3
5
Substitute
3
−y−5
for x in the other equation, x−y=−3.
−
3
1
y−
3
5
−y=−3
Add −
3
y
to −y.
−
3
4
y−
3
5
=−3
Add
3
5
to both sides of the equation.
−
3
4
y=−
3
4
Divide both sides of the equation by −
3
4
, which is the same as multiplying both sides by the reciprocal of the fraction.
y=1
Substitute 1 for y in x=−
3
1
y−
3
5
. Because the resulting equation contains only one variable, you can solve for x directly.
x=
3
−1−5
Add −
3
5
to −
3
1
by finding a common denominator and adding the numerators. Then reduce the fraction to lowest terms if possible.
x=−2
The system is now solved.
x=−2,y=1