Solve 11x − 1 = 21

The solution of 11x − 1 = 21 is x = 2.

11x - 1 = 21\ \Rightarrow\ x = 2

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

The lines y = 11x − 1 and y = 21 meet at x = 2. 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.
$11x - 1 = 21$
2
Add 1 to both sides:
$11x - 1 + 1 = 21 + 1 \ \Rightarrow\ 11x = 22$
3
Divide both sides by 11:
$\frac{11x}{11} = \frac{22}{11} \ \Rightarrow\ x = 2$
4
Check: put x = 2 back into the equation.
$11\cdot2 - 1 = 22 - 1 = 21 \checkmark$

LaTeX source of the formulas on this page

\[ 11x - 1 = 21\ \Rightarrow\ x = 2 \]
\[ 11x - 1 = 21 \]
\[ 11x - 1 + 1 = 21 + 1 \ \Rightarrow\ 11x = 22 \]
\[ \frac{11x}{11} = \frac{22}{11} \ \Rightarrow\ x = 2 \]
\[ 11\cdot2 - 1 = 22 - 1 = 21 \checkmark \]

Trying values of x in 11x − 1 = 21

x	11x − 1	Equals 21?
0	-1	no
1	10	no
2	21	yes
3	32	no
4	43	no

Questions

What is x in 11x − 1 = 21?

The solution of 11x − 1 = 21 is x = 2.

How do you solve 11x − 1 = 21?

Add 1 to both sides to get 11x = 22, then divide both sides by 11 to get x = 2.

How do I check the answer?

Replace x by 2: 11(2) − 1 = 21, which is 21.

Solve 11x − 1 = 21

How to work it out

Trying values of x in 11x − 1 = 21

Questions

Similar equations