Solve 5x − 8 = 7

The solution of 5x − 8 = 7 is x = 3.

5x - 8 = 7\ \Rightarrow\ x = 3

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

The lines y = 5x − 8 and y = 7 meet at x = 3. 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.
$5x - 8 = 7$
2
Add 8 to both sides:
$5x - 8 + 8 = 7 + 8 \ \Rightarrow\ 5x = 15$
3
Divide both sides by 5:
$\frac{5x}{5} = \frac{15}{5} \ \Rightarrow\ x = 3$
4
Check: put x = 3 back into the equation.
$5\cdot3 - 8 = 15 - 8 = 7 \checkmark$

LaTeX source of the formulas on this page

\[ 5x - 8 = 7\ \Rightarrow\ x = 3 \]
\[ 5x - 8 = 7 \]
\[ 5x - 8 + 8 = 7 + 8 \ \Rightarrow\ 5x = 15 \]
\[ \frac{5x}{5} = \frac{15}{5} \ \Rightarrow\ x = 3 \]
\[ 5\cdot3 - 8 = 15 - 8 = 7 \checkmark \]

Trying values of x in 5x − 8 = 7

x	5x − 8	Equals 7?
1	-3	no
2	2	no
3	7	yes
4	12	no
5	17	no

Questions

What is x in 5x − 8 = 7?

The solution of 5x − 8 = 7 is x = 3.

How do you solve 5x − 8 = 7?

Add 8 to both sides to get 5x = 15, then divide both sides by 5 to get x = 3.

How do I check the answer?

Replace x by 3: 5(3) − 8 = 7, which is 7.

Solve 5x − 8 = 7

How to work it out

Trying values of x in 5x − 8 = 7

Questions

Similar equations