Solve 4x + 8 = 68

The solution of 4x + 8 = 68 is x = 15.

4x + 8 = 68\ \Rightarrow\ x = 15

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The lines y = 4x + 8 and y = 68 meet at x = 15. 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.
$4x + 8 = 68$
2
Subtract 8 from both sides:
$4x + 8 - 8 = 68 - 8 \ \Rightarrow\ 4x = 60$
3
Divide both sides by 4:
$\frac{4x}{4} = \frac{60}{4} \ \Rightarrow\ x = 15$
4
Check: put x = 15 back into the equation.
$4\cdot15 + 8 = 60 + 8 = 68 \checkmark$

LaTeX source of the formulas on this page

\[ 4x + 8 = 68\ \Rightarrow\ x = 15 \]
\[ 4x + 8 = 68 \]
\[ 4x + 8 - 8 = 68 - 8 \ \Rightarrow\ 4x = 60 \]
\[ \frac{4x}{4} = \frac{60}{4} \ \Rightarrow\ x = 15 \]
\[ 4\cdot15 + 8 = 60 + 8 = 68 \checkmark \]

Trying values of x in 4x + 8 = 68

x	4x + 8	Equals 68?
13	60	no
14	64	no
15	68	yes
16	72	no
17	76	no

Questions

What is x in 4x + 8 = 68?

The solution of 4x + 8 = 68 is x = 15.

How do you solve 4x + 8 = 68?

Subtract 8 from both sides to get 4x = 60, then divide both sides by 4 to get x = 15.

How do I check the answer?

Replace x by 15: 4(15) + 8 = 68, which is 68.

Solve 4x + 8 = 68

How to work it out

Trying values of x in 4x + 8 = 68

Questions

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