Solve 3x − 11 = 28

The solution of 3x − 11 = 28 is x = 13.

3x - 11 = 28\ \Rightarrow\ x = 13

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

The lines y = 3x − 11 and y = 28 meet at x = 13. 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.
$3x - 11 = 28$
2
Add 11 to both sides:
$3x - 11 + 11 = 28 + 11 \ \Rightarrow\ 3x = 39$
3
Divide both sides by 3:
$\frac{3x}{3} = \frac{39}{3} \ \Rightarrow\ x = 13$
4
Check: put x = 13 back into the equation.
$3\cdot13 - 11 = 39 - 11 = 28 \checkmark$

LaTeX source of the formulas on this page

\[ 3x - 11 = 28\ \Rightarrow\ x = 13 \]
\[ 3x - 11 = 28 \]
\[ 3x - 11 + 11 = 28 + 11 \ \Rightarrow\ 3x = 39 \]
\[ \frac{3x}{3} = \frac{39}{3} \ \Rightarrow\ x = 13 \]
\[ 3\cdot13 - 11 = 39 - 11 = 28 \checkmark \]

Trying values of x in 3x − 11 = 28

x	3x − 11	Equals 28?
11	22	no
12	25	no
13	28	yes
14	31	no
15	34	no

Questions

What is x in 3x − 11 = 28?

The solution of 3x − 11 = 28 is x = 13.

How do you solve 3x − 11 = 28?

Add 11 to both sides to get 3x = 39, then divide both sides by 3 to get x = 13.

How do I check the answer?

Replace x by 13: 3(13) − 11 = 28, which is 28.

Solve 3x − 11 = 28

How to work it out

Trying values of x in 3x − 11 = 28

Questions

Similar equations