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28 votes
28 votes
ANYONE KNOW HOW TO SOLVE THIS!!!! PLEASE HELP ME!!! IT IS SOLVING SYSTEM EQUATIONS BY SUBSTITUTING!!

x+8y=20
4x-y=14

User Vendrel
by
3.1k points

1 Answer

16 votes
16 votes

Answer:

x=4

y=2

Explanation:

x+8y=20

4x−y=14

​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+8y=20,4x−y=14

Choose one of the equations and solve it for x by isolating x on the left hand side of the equal sign.

x+8y=20

Subtract 8y from both sides of the equation.

x=−8y+20

Substitute −8y+20 for x in the other equation, 4x−y=14.

4(−8y+20)−y=14

Multiply 4 times −8y+20.

−32y+80−y=14

Add −32y to −y.

−33y+80=14

Subtract 80 from both sides of the equation.

−33y=−66

Divide both sides by −33.

y=2

Substitute 2 for y in x=−8y+20. Because the resulting equation contains only one variable, you can solve for x directly.

x=−8×2+20

Multiply −8 times 2.

x=−16+20

Add 20 to −16.

x=4

The system is now solved.

x=4,y=2

User Epynic
by
3.3k points