Solve 10x − 9 = 161

The solution of 10x − 9 = 161 is x = 17.

10x - 9 = 161\ \Rightarrow\ x = 17

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The lines y = 10x − 9 and y = 161 meet at x = 17. 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.
$10x - 9 = 161$
2
Add 9 to both sides:
$10x - 9 + 9 = 161 + 9 \ \Rightarrow\ 10x = 170$
3
Divide both sides by 10:
$\frac{10x}{10} = \frac{170}{10} \ \Rightarrow\ x = 17$
4
Check: put x = 17 back into the equation.
$10\cdot17 - 9 = 170 - 9 = 161 \checkmark$

LaTeX source of the formulas on this page

\[ 10x - 9 = 161\ \Rightarrow\ x = 17 \]
\[ 10x - 9 = 161 \]
\[ 10x - 9 + 9 = 161 + 9 \ \Rightarrow\ 10x = 170 \]
\[ \frac{10x}{10} = \frac{170}{10} \ \Rightarrow\ x = 17 \]
\[ 10\cdot17 - 9 = 170 - 9 = 161 \checkmark \]

Trying values of x in 10x − 9 = 161

x	10x − 9	Equals 161?
15	141	no
16	151	no
17	161	yes
18	171	no
19	181	no

Questions

What is x in 10x − 9 = 161?

The solution of 10x − 9 = 161 is x = 17.

How do you solve 10x − 9 = 161?

Add 9 to both sides to get 10x = 170, then divide both sides by 10 to get x = 17.

How do I check the answer?

Replace x by 17: 10(17) − 9 = 161, which is 161.

Solve 10x − 9 = 161

How to work it out

Trying values of x in 10x − 9 = 161

Questions

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