Solve 5x − 8 = 57

The solution of 5x − 8 = 57 is x = 13.

5x - 8 = 57\ \Rightarrow\ x = 13

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

The lines y = 5x − 8 and y = 57 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.
$5x - 8 = 57$
2
Add 8 to both sides:
$5x - 8 + 8 = 57 + 8 \ \Rightarrow\ 5x = 65$
3
Divide both sides by 5:
$\frac{5x}{5} = \frac{65}{5} \ \Rightarrow\ x = 13$
4
Check: put x = 13 back into the equation.
$5\cdot13 - 8 = 65 - 8 = 57 \checkmark$

LaTeX source of the formulas on this page

\[ 5x - 8 = 57\ \Rightarrow\ x = 13 \]
\[ 5x - 8 = 57 \]
\[ 5x - 8 + 8 = 57 + 8 \ \Rightarrow\ 5x = 65 \]
\[ \frac{5x}{5} = \frac{65}{5} \ \Rightarrow\ x = 13 \]
\[ 5\cdot13 - 8 = 65 - 8 = 57 \checkmark \]

Trying values of x in 5x − 8 = 57

x	5x − 8	Equals 57?
11	47	no
12	52	no
13	57	yes
14	62	no
15	67	no

Questions

What is x in 5x − 8 = 57?

The solution of 5x − 8 = 57 is x = 13.

How do you solve 5x − 8 = 57?

Add 8 to both sides to get 5x = 65, then divide both sides by 5 to get x = 13.

How do I check the answer?

Replace x by 13: 5(13) − 8 = 57, which is 57.

Solve 5x − 8 = 57

How to work it out

Trying values of x in 5x − 8 = 57

Questions

Similar equations