Question

7x-8y=10 and x-8y=-26 using elimination

Answer 1

x= 6;

y= 4.

Explanation:

1. Write the equations.

`(1)7x-8y=10\\\\ (2)x-8y=-26\\`

2. Subtract equation 2 from equation 1.

`(1)7x-8y=10\\-\\ (2)x-8y=-26\\--------\\\\6x+0y=36\\ \\6x=36`

3. Solve for x.

`(6x)/(6) =(36)/(6) \\ \\x=6`

4. Use the calculated value of "x" in any of the equation to the value of "y".

For this solution, we are going to use equation 2 to get the value of "y".

`(6)-8y=-26\\\\-8y=-26-6\\ \\-8y=-32\\ \\(-8y)/(-8) =(-32)/(-8) \\ \\y=4`

5. Verify.

If the answers are correct, both equations should return the same value in both sides of the equal (=) sign.

`7(6)-8(4)=10\\ \\42-32=10\\ \\10=10`

That's correct.

`(6)-8(4)=-26\\ \\6-32=-26\\ \\-26=-26`

That's correct.

Hence, the answers are correct.