Answer:
x= -3
y= -8
Explanation:
- 4x−3y=12,7x−3y=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.
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Choose one of the equations and solve it for x by isolating x on the left hand side of the equal sign.
4x−3y=12
Add 3y to both sides of the equation.
4x=3y+12
Divide both sides by 4.
x = 1\4(3y+12)
Multiply 1\4 times 12+3y.
x = 3\4y + 3
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Substitute 3y\4 + 3
for x in the other equation, 7x−3y=3.
7( 3\4y + 3 ) - 3y = 3
Multiply 7 times 3y\4 + 3
21\4y + 21 -3y = 3
Add 21y\4 to -3y
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9\4y = -18
Divide both sides of the equation by 9\4 which is the same as multiplying both sides by the reciprocal of the fraction.
y = −8
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Substitute −8 for y in x = 3\4y + 3. Because the resulting equation contains only one variable, you can solve for x directly.
x = 3\4(-8)+3
Multiply 3\4 times -8
x=−6+3
Add 3 to −6.
x = −3