Solve 2x − 4 = 36

The solution of 2x − 4 = 36 is x = 20.

2x - 4 = 36\ \Rightarrow\ x = 20

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The lines y = 2x − 4 and y = 36 meet at x = 20. 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.
$2x - 4 = 36$
2
Add 4 to both sides:
$2x - 4 + 4 = 36 + 4 \ \Rightarrow\ 2x = 40$
3
Divide both sides by 2:
$\frac{2x}{2} = \frac{40}{2} \ \Rightarrow\ x = 20$
4
Check: put x = 20 back into the equation.
$2\cdot20 - 4 = 40 - 4 = 36 \checkmark$

LaTeX source of the formulas on this page

\[ 2x - 4 = 36\ \Rightarrow\ x = 20 \]
\[ 2x - 4 = 36 \]
\[ 2x - 4 + 4 = 36 + 4 \ \Rightarrow\ 2x = 40 \]
\[ \frac{2x}{2} = \frac{40}{2} \ \Rightarrow\ x = 20 \]
\[ 2\cdot20 - 4 = 40 - 4 = 36 \checkmark \]

Trying values of x in 2x − 4 = 36

x	2x − 4	Equals 36?
18	32	no
19	34	no
20	36	yes
21	38	no
22	40	no

Questions

What is x in 2x − 4 = 36?

The solution of 2x − 4 = 36 is x = 20.

How do you solve 2x − 4 = 36?

Add 4 to both sides to get 2x = 40, then divide both sides by 2 to get x = 20.

How do I check the answer?

Replace x by 20: 2(20) − 4 = 36, which is 36.

Solve 2x − 4 = 36

How to work it out

Trying values of x in 2x − 4 = 36

Questions

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