Solve 7x − 15 = −1

The solution of 7x − 15 = −1 is x = 2.

7x - 15 = -1\ \Rightarrow\ x = 2

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

The lines y = 7x − 15 and y = -1 meet at x = 2. 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.
$7x - 15 = -1$
2
Add 15 to both sides:
$7x - 15 + 15 = -1 + 15 \ \Rightarrow\ 7x = 14$
3
Divide both sides by 7:
$\frac{7x}{7} = \frac{14}{7} \ \Rightarrow\ x = 2$
4
Check: put x = 2 back into the equation.
$7\cdot2 - 15 = 14 - 15 = -1 \checkmark$

LaTeX source of the formulas on this page

\[ 7x - 15 = -1\ \Rightarrow\ x = 2 \]
\[ 7x - 15 = -1 \]
\[ 7x - 15 + 15 = -1 + 15 \ \Rightarrow\ 7x = 14 \]
\[ \frac{7x}{7} = \frac{14}{7} \ \Rightarrow\ x = 2 \]
\[ 7\cdot2 - 15 = 14 - 15 = -1 \checkmark \]

Trying values of x in 7x − 15 = −1

x	7x − 15	Equals -1?
0	-15	no
1	-8	no
2	-1	yes
3	6	no
4	13	no

Questions

What is x in 7x − 15 = −1?

The solution of 7x − 15 = −1 is x = 2.

How do you solve 7x − 15 = −1?

Add 15 to both sides to get 7x = 14, then divide both sides by 7 to get x = 2.

How do I check the answer?

Replace x by 2: 7(2) − 15 = -1, which is -1.

Solve 7x − 15 = −1

How to work it out

Trying values of x in 7x − 15 = −1

Questions

Similar equations