Solve 2x − 11 = 9

The solution of 2x − 11 = 9 is x = 10.

2x - 11 = 9\ \Rightarrow\ x = 10

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

The lines y = 2x − 11 and y = 9 meet at x = 10. 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.
$2x - 11 = 9$
2
Add 11 to both sides:
$2x - 11 + 11 = 9 + 11 \ \Rightarrow\ 2x = 20$
3
Divide both sides by 2:
$\frac{2x}{2} = \frac{20}{2} \ \Rightarrow\ x = 10$
4
Check: put x = 10 back into the equation.
$2\cdot10 - 11 = 20 - 11 = 9 \checkmark$

LaTeX source of the formulas on this page

\[ 2x - 11 = 9\ \Rightarrow\ x = 10 \]
\[ 2x - 11 = 9 \]
\[ 2x - 11 + 11 = 9 + 11 \ \Rightarrow\ 2x = 20 \]
\[ \frac{2x}{2} = \frac{20}{2} \ \Rightarrow\ x = 10 \]
\[ 2\cdot10 - 11 = 20 - 11 = 9 \checkmark \]

Trying values of x in 2x − 11 = 9

x	2x − 11	Equals 9?
8	5	no
9	7	no
10	9	yes
11	11	no
12	13	no

Questions

What is x in 2x − 11 = 9?

The solution of 2x − 11 = 9 is x = 10.

How do you solve 2x − 11 = 9?

Add 11 to both sides to get 2x = 20, then divide both sides by 2 to get x = 10.

How do I check the answer?

Replace x by 10: 2(10) − 11 = 9, which is 9.

Solve 2x − 11 = 9

How to work it out

Trying values of x in 2x − 11 = 9

Questions

Similar equations