Solve 7x − 7 = 70

The solution of 7x − 7 = 70 is x = 11.

7x - 7 = 70\ \Rightarrow\ x = 11

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The lines y = 7x − 7 and y = 70 meet at x = 11. 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.
$7x - 7 = 70$
2
Add 7 to both sides:
$7x - 7 + 7 = 70 + 7 \ \Rightarrow\ 7x = 77$
3
Divide both sides by 7:
$\frac{7x}{7} = \frac{77}{7} \ \Rightarrow\ x = 11$
4
Check: put x = 11 back into the equation.
$7\cdot11 - 7 = 77 - 7 = 70 \checkmark$

LaTeX source of the formulas on this page

\[ 7x - 7 = 70\ \Rightarrow\ x = 11 \]
\[ 7x - 7 = 70 \]
\[ 7x - 7 + 7 = 70 + 7 \ \Rightarrow\ 7x = 77 \]
\[ \frac{7x}{7} = \frac{77}{7} \ \Rightarrow\ x = 11 \]
\[ 7\cdot11 - 7 = 77 - 7 = 70 \checkmark \]

Trying values of x in 7x − 7 = 70

x	7x − 7	Equals 70?
9	56	no
10	63	no
11	70	yes
12	77	no
13	84	no

Questions

What is x in 7x − 7 = 70?

The solution of 7x − 7 = 70 is x = 11.

How do you solve 7x − 7 = 70?

Add 7 to both sides to get 7x = 77, then divide both sides by 7 to get x = 11.

How do I check the answer?

Replace x by 11: 7(11) − 7 = 70, which is 70.

Solve 7x − 7 = 70

How to work it out

Trying values of x in 7x − 7 = 70

Questions

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