Solve 9x − 8 = 64

The solution of 9x − 8 = 64 is x = 8.

9x - 8 = 64\ \Rightarrow\ x = 8

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

The lines y = 9x − 8 and y = 64 meet at x = 8. 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.
$9x - 8 = 64$
2
Add 8 to both sides:
$9x - 8 + 8 = 64 + 8 \ \Rightarrow\ 9x = 72$
3
Divide both sides by 9:
$\frac{9x}{9} = \frac{72}{9} \ \Rightarrow\ x = 8$
4
Check: put x = 8 back into the equation.
$9\cdot8 - 8 = 72 - 8 = 64 \checkmark$

LaTeX source of the formulas on this page

\[ 9x - 8 = 64\ \Rightarrow\ x = 8 \]
\[ 9x - 8 = 64 \]
\[ 9x - 8 + 8 = 64 + 8 \ \Rightarrow\ 9x = 72 \]
\[ \frac{9x}{9} = \frac{72}{9} \ \Rightarrow\ x = 8 \]
\[ 9\cdot8 - 8 = 72 - 8 = 64 \checkmark \]

Trying values of x in 9x − 8 = 64

x	9x − 8	Equals 64?
6	46	no
7	55	no
8	64	yes
9	73	no
10	82	no

Questions

What is x in 9x − 8 = 64?

The solution of 9x − 8 = 64 is x = 8.

How do you solve 9x − 8 = 64?

Add 8 to both sides to get 9x = 72, then divide both sides by 9 to get x = 8.

How do I check the answer?

Replace x by 8: 9(8) − 8 = 64, which is 64.

Solve 9x − 8 = 64

How to work it out

Trying values of x in 9x − 8 = 64

Questions

Similar equations