Solve 10x − 10 = 140

The solution of 10x − 10 = 140 is x = 15.

10x - 10 = 140\ \Rightarrow\ x = 15

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The lines y = 10x − 10 and y = 140 meet at x = 15. 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.
$10x - 10 = 140$
2
Add 10 to both sides:
$10x - 10 + 10 = 140 + 10 \ \Rightarrow\ 10x = 150$
3
Divide both sides by 10:
$\frac{10x}{10} = \frac{150}{10} \ \Rightarrow\ x = 15$
4
Check: put x = 15 back into the equation.
$10\cdot15 - 10 = 150 - 10 = 140 \checkmark$

LaTeX source of the formulas on this page

\[ 10x - 10 = 140\ \Rightarrow\ x = 15 \]
\[ 10x - 10 = 140 \]
\[ 10x - 10 + 10 = 140 + 10 \ \Rightarrow\ 10x = 150 \]
\[ \frac{10x}{10} = \frac{150}{10} \ \Rightarrow\ x = 15 \]
\[ 10\cdot15 - 10 = 150 - 10 = 140 \checkmark \]

Trying values of x in 10x − 10 = 140

x	10x − 10	Equals 140?
13	120	no
14	130	no
15	140	yes
16	150	no
17	160	no

Questions

What is x in 10x − 10 = 140?

The solution of 10x − 10 = 140 is x = 15.

How do you solve 10x − 10 = 140?

Add 10 to both sides to get 10x = 150, then divide both sides by 10 to get x = 15.

How do I check the answer?

Replace x by 15: 10(15) − 10 = 140, which is 140.

Solve 10x − 10 = 140

How to work it out

Trying values of x in 10x − 10 = 140

Questions

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