Question

Solve for x.

y=7x−7z−9

1) x=y−z−9/7

2) x=y−7z−9/7

3) x=y+7z+9/7

4) x=y+z+9/7

Answer 1

4) ?

there is something wrong. none of the solution options fit to the original equation. you must have missed something.

maybe it is 7y=... to begin with. or there is a y/7 in the solution options.

Explanation:

this is the result, if your original equation is correct :

y = 7x - 7z - 9

y + 7z = 7x - 9

y + 7z + 9 = 7x

x = y/7 + z + 9/7

we always have to apply an operation to both sides of the "=" sign to keep the overall value and validity of the expression unchanged.

so, as mentioned, either we started with 7y, or the answer has to contain y/7.

or something else is wrong here entirely.

Answer 2

3) x = (y + 7z + 9)/7

Explanation:

Now we have to,

→ Find the required value of x.

The equation is,

→ y = 7x - 7z - 9

Then the value of x will be,

→ y = 7x - 7z - 9

→ y - 7x = -7z - 9

→ -7x = -y - 7z - 9

→ 7x = y + 7z + 9

→ x = (y + 7z + 9)/7

→ x = (y/7) + (7z/7) + (9/7)

→ x = (y/7) + z + (9/7)

Hence, option (3) is correct.