Solve 2x − 8 = 28

The solution of 2x − 8 = 28 is x = 18.

2x - 8 = 28\ \Rightarrow\ x = 18

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The lines y = 2x − 8 and y = 28 meet at x = 18. 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.
$2x - 8 = 28$
2
Add 8 to both sides:
$2x - 8 + 8 = 28 + 8 \ \Rightarrow\ 2x = 36$
3
Divide both sides by 2:
$\frac{2x}{2} = \frac{36}{2} \ \Rightarrow\ x = 18$
4
Check: put x = 18 back into the equation.
$2\cdot18 - 8 = 36 - 8 = 28 \checkmark$

LaTeX source of the formulas on this page

\[ 2x - 8 = 28\ \Rightarrow\ x = 18 \]
\[ 2x - 8 = 28 \]
\[ 2x - 8 + 8 = 28 + 8 \ \Rightarrow\ 2x = 36 \]
\[ \frac{2x}{2} = \frac{36}{2} \ \Rightarrow\ x = 18 \]
\[ 2\cdot18 - 8 = 36 - 8 = 28 \checkmark \]

Trying values of x in 2x − 8 = 28

x	2x − 8	Equals 28?
16	24	no
17	26	no
18	28	yes
19	30	no
20	32	no

Questions

What is x in 2x − 8 = 28?

The solution of 2x − 8 = 28 is x = 18.

How do you solve 2x − 8 = 28?

Add 8 to both sides to get 2x = 36, then divide both sides by 2 to get x = 18.

How do I check the answer?

Replace x by 18: 2(18) − 8 = 28, which is 28.

Solve 2x − 8 = 28

How to work it out

Trying values of x in 2x − 8 = 28

Questions

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