Solve 9x − 1 = 8

The solution of 9x − 1 = 8 is x = 1.

9x - 1 = 8\ \Rightarrow\ x = 1

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The lines y = 9x − 1 and y = 8 meet at x = 1. 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.
$9x - 1 = 8$
2
Add 1 to both sides:
$9x - 1 + 1 = 8 + 1 \ \Rightarrow\ 9x = 9$
3
Divide both sides by 9:
$\frac{9x}{9} = \frac{9}{9} \ \Rightarrow\ x = 1$
4
Check: put x = 1 back into the equation.
$9\cdot1 - 1 = 9 - 1 = 8 \checkmark$

LaTeX source of the formulas on this page

\[ 9x - 1 = 8\ \Rightarrow\ x = 1 \]
\[ 9x - 1 = 8 \]
\[ 9x - 1 + 1 = 8 + 1 \ \Rightarrow\ 9x = 9 \]
\[ \frac{9x}{9} = \frac{9}{9} \ \Rightarrow\ x = 1 \]
\[ 9\cdot1 - 1 = 9 - 1 = 8 \checkmark \]

Trying values of x in 9x − 1 = 8

x	9x − 1	Equals 8?
-1	-10	no
0	-1	no
1	8	yes
2	17	no
3	26	no

Questions

What is x in 9x − 1 = 8?

The solution of 9x − 1 = 8 is x = 1.

How do you solve 9x − 1 = 8?

Add 1 to both sides to get 9x = 9, then divide both sides by 9 to get x = 1.

How do I check the answer?

Replace x by 1: 9(1) − 1 = 8, which is 8.

Solve 9x − 1 = 8

How to work it out

Trying values of x in 9x − 1 = 8

Questions

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