Solve 4x − 12 = 0

The solution of 4x − 12 = 0 is x = 3.

4x - 12 = 0\ \Rightarrow\ x = 3

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The lines y = 4x − 12 and y = 0 meet at x = 3. 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.
$4x - 12 = 0$
2
Add 12 to both sides:
$4x - 12 + 12 = 0 + 12 \ \Rightarrow\ 4x = 12$
3
Divide both sides by 4:
$\frac{4x}{4} = \frac{12}{4} \ \Rightarrow\ x = 3$
4
Check: put x = 3 back into the equation.
$4\cdot3 - 12 = 12 - 12 = 0 \checkmark$

LaTeX source of the formulas on this page

\[ 4x - 12 = 0\ \Rightarrow\ x = 3 \]
\[ 4x - 12 = 0 \]
\[ 4x - 12 + 12 = 0 + 12 \ \Rightarrow\ 4x = 12 \]
\[ \frac{4x}{4} = \frac{12}{4} \ \Rightarrow\ x = 3 \]
\[ 4\cdot3 - 12 = 12 - 12 = 0 \checkmark \]

Trying values of x in 4x − 12 = 0

x	4x − 12	Equals 0?
1	-8	no
2	-4	no
3	0	yes
4	4	no
5	8	no

Questions

What is x in 4x − 12 = 0?

The solution of 4x − 12 = 0 is x = 3.

How do you solve 4x − 12 = 0?

Add 12 to both sides to get 4x = 12, then divide both sides by 4 to get x = 3.

How do I check the answer?

Replace x by 3: 4(3) − 12 = 0, which is 0.

Solve 4x − 12 = 0

How to work it out

Trying values of x in 4x − 12 = 0

Questions

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