Solve 8x + 4 = 20

The solution of 8x + 4 = 20 is x = 2.

8x + 4 = 20\ \Rightarrow\ x = 2

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The lines y = 8x + 4 and y = 20 meet at x = 2. 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 addition, then the multiplication.
$8x + 4 = 20$
2
Subtract 4 from both sides:
$8x + 4 - 4 = 20 - 4 \ \Rightarrow\ 8x = 16$
3
Divide both sides by 8:
$\frac{8x}{8} = \frac{16}{8} \ \Rightarrow\ x = 2$
4
Check: put x = 2 back into the equation.
$8\cdot2 + 4 = 16 + 4 = 20 \checkmark$

LaTeX source of the formulas on this page

\[ 8x + 4 = 20\ \Rightarrow\ x = 2 \]
\[ 8x + 4 = 20 \]
\[ 8x + 4 - 4 = 20 - 4 \ \Rightarrow\ 8x = 16 \]
\[ \frac{8x}{8} = \frac{16}{8} \ \Rightarrow\ x = 2 \]
\[ 8\cdot2 + 4 = 16 + 4 = 20 \checkmark \]

Trying values of x in 8x + 4 = 20

x	8x + 4	Equals 20?
0	4	no
1	12	no
2	20	yes
3	28	no
4	36	no

Questions

What is x in 8x + 4 = 20?

The solution of 8x + 4 = 20 is x = 2.

How do you solve 8x + 4 = 20?

Subtract 4 from both sides to get 8x = 16, then divide both sides by 8 to get x = 2.

How do I check the answer?

Replace x by 2: 8(2) + 4 = 20, which is 20.

Solve 8x + 4 = 20

How to work it out

Trying values of x in 8x + 4 = 20

Questions

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