Solve 3x − 7 = 17

The solution of 3x − 7 = 17 is x = 8.

3x - 7 = 17\ \Rightarrow\ x = 8

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

The lines y = 3x − 7 and y = 17 meet at x = 8. 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.
$3x - 7 = 17$
2
Add 7 to both sides:
$3x - 7 + 7 = 17 + 7 \ \Rightarrow\ 3x = 24$
3
Divide both sides by 3:
$\frac{3x}{3} = \frac{24}{3} \ \Rightarrow\ x = 8$
4
Check: put x = 8 back into the equation.
$3\cdot8 - 7 = 24 - 7 = 17 \checkmark$

LaTeX source of the formulas on this page

\[ 3x - 7 = 17\ \Rightarrow\ x = 8 \]
\[ 3x - 7 = 17 \]
\[ 3x - 7 + 7 = 17 + 7 \ \Rightarrow\ 3x = 24 \]
\[ \frac{3x}{3} = \frac{24}{3} \ \Rightarrow\ x = 8 \]
\[ 3\cdot8 - 7 = 24 - 7 = 17 \checkmark \]

Trying values of x in 3x − 7 = 17

x	3x − 7	Equals 17?
6	11	no
7	14	no
8	17	yes
9	20	no
10	23	no

Questions

What is x in 3x − 7 = 17?

The solution of 3x − 7 = 17 is x = 8.

How do you solve 3x − 7 = 17?

Add 7 to both sides to get 3x = 24, then divide both sides by 3 to get x = 8.

How do I check the answer?

Replace x by 8: 3(8) − 7 = 17, which is 17.

Solve 3x − 7 = 17

How to work it out

Trying values of x in 3x − 7 = 17

Questions

Similar equations