Solve 7x − 13 = 127

The solution of 7x − 13 = 127 is x = 20.

7x - 13 = 127\ \Rightarrow\ x = 20

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

The lines y = 7x − 13 and y = 127 meet at x = 20. 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.
$7x - 13 = 127$
2
Add 13 to both sides:
$7x - 13 + 13 = 127 + 13 \ \Rightarrow\ 7x = 140$
3
Divide both sides by 7:
$\frac{7x}{7} = \frac{140}{7} \ \Rightarrow\ x = 20$
4
Check: put x = 20 back into the equation.
$7\cdot20 - 13 = 140 - 13 = 127 \checkmark$

LaTeX source of the formulas on this page

\[ 7x - 13 = 127\ \Rightarrow\ x = 20 \]
\[ 7x - 13 = 127 \]
\[ 7x - 13 + 13 = 127 + 13 \ \Rightarrow\ 7x = 140 \]
\[ \frac{7x}{7} = \frac{140}{7} \ \Rightarrow\ x = 20 \]
\[ 7\cdot20 - 13 = 140 - 13 = 127 \checkmark \]

Trying values of x in 7x − 13 = 127

x	7x − 13	Equals 127?
18	113	no
19	120	no
20	127	yes
21	134	no
22	141	no

Questions

What is x in 7x − 13 = 127?

The solution of 7x − 13 = 127 is x = 20.

How do you solve 7x − 13 = 127?

Add 13 to both sides to get 7x = 140, then divide both sides by 7 to get x = 20.

How do I check the answer?

Replace x by 20: 7(20) − 13 = 127, which is 127.

Solve 7x − 13 = 127

How to work it out

Trying values of x in 7x − 13 = 127

Questions

Similar equations