Solve 2x − 11 = 21

The solution of 2x − 11 = 21 is x = 16.

2x - 11 = 21\ \Rightarrow\ x = 16

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

The lines y = 2x − 11 and y = 21 meet at x = 16. 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.
$2x - 11 = 21$
2
Add 11 to both sides:
$2x - 11 + 11 = 21 + 11 \ \Rightarrow\ 2x = 32$
3
Divide both sides by 2:
$\frac{2x}{2} = \frac{32}{2} \ \Rightarrow\ x = 16$
4
Check: put x = 16 back into the equation.
$2\cdot16 - 11 = 32 - 11 = 21 \checkmark$

LaTeX source of the formulas on this page

\[ 2x - 11 = 21\ \Rightarrow\ x = 16 \]
\[ 2x - 11 = 21 \]
\[ 2x - 11 + 11 = 21 + 11 \ \Rightarrow\ 2x = 32 \]
\[ \frac{2x}{2} = \frac{32}{2} \ \Rightarrow\ x = 16 \]
\[ 2\cdot16 - 11 = 32 - 11 = 21 \checkmark \]

Trying values of x in 2x − 11 = 21

x	2x − 11	Equals 21?
14	17	no
15	19	no
16	21	yes
17	23	no
18	25	no

Questions

What is x in 2x − 11 = 21?

The solution of 2x − 11 = 21 is x = 16.

How do you solve 2x − 11 = 21?

Add 11 to both sides to get 2x = 32, then divide both sides by 2 to get x = 16.

How do I check the answer?

Replace x by 16: 2(16) − 11 = 21, which is 21.

Solve 2x − 11 = 21

How to work it out

Trying values of x in 2x − 11 = 21

Questions

Similar equations