Solve 7x − 15 = 27

The solution of 7x − 15 = 27 is x = 6.

7x - 15 = 27\ \Rightarrow\ x = 6

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

The lines y = 7x − 15 and y = 27 meet at x = 6. 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.
$7x - 15 = 27$
2
Add 15 to both sides:
$7x - 15 + 15 = 27 + 15 \ \Rightarrow\ 7x = 42$
3
Divide both sides by 7:
$\frac{7x}{7} = \frac{42}{7} \ \Rightarrow\ x = 6$
4
Check: put x = 6 back into the equation.
$7\cdot6 - 15 = 42 - 15 = 27 \checkmark$

LaTeX source of the formulas on this page

\[ 7x - 15 = 27\ \Rightarrow\ x = 6 \]
\[ 7x - 15 = 27 \]
\[ 7x - 15 + 15 = 27 + 15 \ \Rightarrow\ 7x = 42 \]
\[ \frac{7x}{7} = \frac{42}{7} \ \Rightarrow\ x = 6 \]
\[ 7\cdot6 - 15 = 42 - 15 = 27 \checkmark \]

Trying values of x in 7x − 15 = 27

x	7x − 15	Equals 27?
4	13	no
5	20	no
6	27	yes
7	34	no
8	41	no

Questions

What is x in 7x − 15 = 27?

The solution of 7x − 15 = 27 is x = 6.

How do you solve 7x − 15 = 27?

Add 15 to both sides to get 7x = 42, then divide both sides by 7 to get x = 6.

How do I check the answer?

Replace x by 6: 7(6) − 15 = 27, which is 27.

Solve 7x − 15 = 27

How to work it out

Trying values of x in 7x − 15 = 27

Questions

Similar equations