Solve 7x − 7 = 126

The solution of 7x − 7 = 126 is x = 19.

7x - 7 = 126\ \Rightarrow\ x = 19

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The lines y = 7x − 7 and y = 126 meet at x = 19. The solution of the equation is the x-coordinate of the point where the two sides are equal.

How to work it out

1
The goal is to get x alone. Undo the operations in the opposite order: first the subtraction, then the multiplication.
$7x - 7 = 126$
2
Add 7 to both sides:
$7x - 7 + 7 = 126 + 7 \ \Rightarrow\ 7x = 133$
3
Divide both sides by 7:
$\frac{7x}{7} = \frac{133}{7} \ \Rightarrow\ x = 19$
4
Check: put x = 19 back into the equation.
$7\cdot19 - 7 = 133 - 7 = 126 \checkmark$

LaTeX source of the formulas on this page

\[ 7x - 7 = 126\ \Rightarrow\ x = 19 \]
\[ 7x - 7 = 126 \]
\[ 7x - 7 + 7 = 126 + 7 \ \Rightarrow\ 7x = 133 \]
\[ \frac{7x}{7} = \frac{133}{7} \ \Rightarrow\ x = 19 \]
\[ 7\cdot19 - 7 = 133 - 7 = 126 \checkmark \]

Trying values of x in 7x − 7 = 126

x	7x − 7	Equals 126?
17	112	no
18	119	no
19	126	yes
20	133	no
21	140	no

Questions

What is x in 7x − 7 = 126?

The solution of 7x − 7 = 126 is x = 19.

How do you solve 7x − 7 = 126?

Add 7 to both sides to get 7x = 133, then divide both sides by 7 to get x = 19.

How do I check the answer?

Replace x by 19: 7(19) − 7 = 126, which is 126.

Solve 7x − 7 = 126

How to work it out

Trying values of x in 7x − 7 = 126

Questions

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