Solve 3x − 1 = −28

The solution of 3x − 1 = −28 is x = -9.

3x - 1 = -28\ \Rightarrow\ x = -9

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

The lines y = 3x − 1 and y = -28 meet at x = -9. 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.
$3x - 1 = -28$
2
Add 1 to both sides:
$3x - 1 + 1 = -28 + 1 \ \Rightarrow\ 3x = -27$
3
Divide both sides by 3:
$\frac{3x}{3} = \frac{-27}{3} \ \Rightarrow\ x = -9$
4
Check: put x = -9 back into the equation.
$3\cdot(-9) - 1 = -27 - 1 = -28 \checkmark$

LaTeX source of the formulas on this page

\[ 3x - 1 = -28\ \Rightarrow\ x = -9 \]
\[ 3x - 1 = -28 \]
\[ 3x - 1 + 1 = -28 + 1 \ \Rightarrow\ 3x = -27 \]
\[ \frac{3x}{3} = \frac{-27}{3} \ \Rightarrow\ x = -9 \]
\[ 3\cdot(-9) - 1 = -27 - 1 = -28 \checkmark \]

Trying values of x in 3x − 1 = −28

x	3x − 1	Equals -28?
-11	-34	no
-10	-31	no
-9	-28	yes
-8	-25	no
-7	-22	no

Questions

What is x in 3x − 1 = −28?

The solution of 3x − 1 = −28 is x = -9.

How do you solve 3x − 1 = −28?

Add 1 to both sides to get 3x = -27, then divide both sides by 3 to get x = -9.

How do I check the answer?

Replace x by -9: 3(-9) − 1 = -28, which is -28.

Solve 3x − 1 = −28

How to work it out

Trying values of x in 3x − 1 = −28

Questions

Similar equations