Solve 8x − 4 = 36

The solution of 8x − 4 = 36 is x = 5.

8x - 4 = 36\ \Rightarrow\ x = 5

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The lines y = 8x − 4 and y = 36 meet at x = 5. 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.
$8x - 4 = 36$
2
Add 4 to both sides:
$8x - 4 + 4 = 36 + 4 \ \Rightarrow\ 8x = 40$
3
Divide both sides by 8:
$\frac{8x}{8} = \frac{40}{8} \ \Rightarrow\ x = 5$
4
Check: put x = 5 back into the equation.
$8\cdot5 - 4 = 40 - 4 = 36 \checkmark$

LaTeX source of the formulas on this page

\[ 8x - 4 = 36\ \Rightarrow\ x = 5 \]
\[ 8x - 4 = 36 \]
\[ 8x - 4 + 4 = 36 + 4 \ \Rightarrow\ 8x = 40 \]
\[ \frac{8x}{8} = \frac{40}{8} \ \Rightarrow\ x = 5 \]
\[ 8\cdot5 - 4 = 40 - 4 = 36 \checkmark \]

Trying values of x in 8x − 4 = 36

x	8x − 4	Equals 36?
3	20	no
4	28	no
5	36	yes
6	44	no
7	52	no

Questions

What is x in 8x − 4 = 36?

The solution of 8x − 4 = 36 is x = 5.

How do you solve 8x − 4 = 36?

Add 4 to both sides to get 8x = 40, then divide both sides by 8 to get x = 5.

How do I check the answer?

Replace x by 5: 8(5) − 4 = 36, which is 36.

Solve 8x − 4 = 36

How to work it out

Trying values of x in 8x − 4 = 36

Questions

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