Solve 9x − 12 = −3

The solution of 9x − 12 = −3 is x = 1.

9x - 12 = -3\ \Rightarrow\ x = 1

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The lines y = 9x − 12 and y = -3 meet at x = 1. 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.
$9x - 12 = -3$
2
Add 12 to both sides:
$9x - 12 + 12 = -3 + 12 \ \Rightarrow\ 9x = 9$
3
Divide both sides by 9:
$\frac{9x}{9} = \frac{9}{9} \ \Rightarrow\ x = 1$
4
Check: put x = 1 back into the equation.
$9\cdot1 - 12 = 9 - 12 = -3 \checkmark$

LaTeX source of the formulas on this page

\[ 9x - 12 = -3\ \Rightarrow\ x = 1 \]
\[ 9x - 12 = -3 \]
\[ 9x - 12 + 12 = -3 + 12 \ \Rightarrow\ 9x = 9 \]
\[ \frac{9x}{9} = \frac{9}{9} \ \Rightarrow\ x = 1 \]
\[ 9\cdot1 - 12 = 9 - 12 = -3 \checkmark \]

Trying values of x in 9x − 12 = −3

x	9x − 12	Equals -3?
-1	-21	no
0	-12	no
1	-3	yes
2	6	no
3	15	no

Questions

What is x in 9x − 12 = −3?

The solution of 9x − 12 = −3 is x = 1.

How do you solve 9x − 12 = −3?

Add 12 to both sides to get 9x = 9, then divide both sides by 9 to get x = 1.

How do I check the answer?

Replace x by 1: 9(1) − 12 = -3, which is -3.

Solve 9x − 12 = −3

How to work it out

Trying values of x in 9x − 12 = −3

Questions

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