Solve 9x − 10 = 125

The solution of 9x − 10 = 125 is x = 15.

9x - 10 = 125\ \Rightarrow\ x = 15

Explain it step by step in chat Make a short video of it

The lines y = 9x − 10 and y = 125 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.
$9x - 10 = 125$
2
Add 10 to both sides:
$9x - 10 + 10 = 125 + 10 \ \Rightarrow\ 9x = 135$
3
Divide both sides by 9:
$\frac{9x}{9} = \frac{135}{9} \ \Rightarrow\ x = 15$
4
Check: put x = 15 back into the equation.
$9\cdot15 - 10 = 135 - 10 = 125 \checkmark$

LaTeX source of the formulas on this page

\[ 9x - 10 = 125\ \Rightarrow\ x = 15 \]
\[ 9x - 10 = 125 \]
\[ 9x - 10 + 10 = 125 + 10 \ \Rightarrow\ 9x = 135 \]
\[ \frac{9x}{9} = \frac{135}{9} \ \Rightarrow\ x = 15 \]
\[ 9\cdot15 - 10 = 135 - 10 = 125 \checkmark \]

Trying values of x in 9x − 10 = 125

x	9x − 10	Equals 125?
13	107	no
14	116	no
15	125	yes
16	134	no
17	143	no

Questions

What is x in 9x − 10 = 125?

The solution of 9x − 10 = 125 is x = 15.

How do you solve 9x − 10 = 125?

Add 10 to both sides to get 9x = 135, then divide both sides by 9 to get x = 15.

How do I check the answer?

Replace x by 15: 9(15) − 10 = 125, which is 125.

Solve 9x − 10 = 125

How to work it out

Trying values of x in 9x − 10 = 125

Questions

Similar equations