Solve 8x − 12 = 124

The solution of 8x − 12 = 124 is x = 17.

8x - 12 = 124\ \Rightarrow\ x = 17

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The lines y = 8x − 12 and y = 124 meet at x = 17. 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.
$8x - 12 = 124$
2
Add 12 to both sides:
$8x - 12 + 12 = 124 + 12 \ \Rightarrow\ 8x = 136$
3
Divide both sides by 8:
$\frac{8x}{8} = \frac{136}{8} \ \Rightarrow\ x = 17$
4
Check: put x = 17 back into the equation.
$8\cdot17 - 12 = 136 - 12 = 124 \checkmark$

LaTeX source of the formulas on this page

\[ 8x - 12 = 124\ \Rightarrow\ x = 17 \]
\[ 8x - 12 = 124 \]
\[ 8x - 12 + 12 = 124 + 12 \ \Rightarrow\ 8x = 136 \]
\[ \frac{8x}{8} = \frac{136}{8} \ \Rightarrow\ x = 17 \]
\[ 8\cdot17 - 12 = 136 - 12 = 124 \checkmark \]

Trying values of x in 8x − 12 = 124

x	8x − 12	Equals 124?
15	108	no
16	116	no
17	124	yes
18	132	no
19	140	no

Questions

What is x in 8x − 12 = 124?

The solution of 8x − 12 = 124 is x = 17.

How do you solve 8x − 12 = 124?

Add 12 to both sides to get 8x = 136, then divide both sides by 8 to get x = 17.

How do I check the answer?

Replace x by 17: 8(17) − 12 = 124, which is 124.

Solve 8x − 12 = 124

How to work it out

Trying values of x in 8x − 12 = 124

Questions

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