Solve 3x + 8 = 47

The solution of 3x + 8 = 47 is x = 13.

3x + 8 = 47\ \Rightarrow\ x = 13

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

The lines y = 3x + 8 and y = 47 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 addition, then the multiplication.
$3x + 8 = 47$
2
Subtract 8 from both sides:
$3x + 8 - 8 = 47 - 8 \ \Rightarrow\ 3x = 39$
3
Divide both sides by 3:
$\frac{3x}{3} = \frac{39}{3} \ \Rightarrow\ x = 13$
4
Check: put x = 13 back into the equation.
$3\cdot13 + 8 = 39 + 8 = 47 \checkmark$

LaTeX source of the formulas on this page

\[ 3x + 8 = 47\ \Rightarrow\ x = 13 \]
\[ 3x + 8 = 47 \]
\[ 3x + 8 - 8 = 47 - 8 \ \Rightarrow\ 3x = 39 \]
\[ \frac{3x}{3} = \frac{39}{3} \ \Rightarrow\ x = 13 \]
\[ 3\cdot13 + 8 = 39 + 8 = 47 \checkmark \]

Trying values of x in 3x + 8 = 47

x	3x + 8	Equals 47?
11	41	no
12	44	no
13	47	yes
14	50	no
15	53	no

Questions

What is x in 3x + 8 = 47?

The solution of 3x + 8 = 47 is x = 13.

How do you solve 3x + 8 = 47?

Subtract 8 from 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) + 8 = 47, which is 47.

Solve 3x + 8 = 47

How to work it out

Trying values of x in 3x + 8 = 47

Questions

Similar equations