Solve 5x − 4 = 51

The solution of 5x − 4 = 51 is x = 11.

5x - 4 = 51\ \Rightarrow\ x = 11

Explain it step by step in chat Make a short video of it

The lines y = 5x − 4 and y = 51 meet at x = 11. 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.
$5x - 4 = 51$
2
Add 4 to both sides:
$5x - 4 + 4 = 51 + 4 \ \Rightarrow\ 5x = 55$
3
Divide both sides by 5:
$\frac{5x}{5} = \frac{55}{5} \ \Rightarrow\ x = 11$
4
Check: put x = 11 back into the equation.
$5\cdot11 - 4 = 55 - 4 = 51 \checkmark$

LaTeX source of the formulas on this page

\[ 5x - 4 = 51\ \Rightarrow\ x = 11 \]
\[ 5x - 4 = 51 \]
\[ 5x - 4 + 4 = 51 + 4 \ \Rightarrow\ 5x = 55 \]
\[ \frac{5x}{5} = \frac{55}{5} \ \Rightarrow\ x = 11 \]
\[ 5\cdot11 - 4 = 55 - 4 = 51 \checkmark \]

Trying values of x in 5x − 4 = 51

x	5x − 4	Equals 51?
9	41	no
10	46	no
11	51	yes
12	56	no
13	61	no

Questions

What is x in 5x − 4 = 51?

The solution of 5x − 4 = 51 is x = 11.

How do you solve 5x − 4 = 51?

Add 4 to both sides to get 5x = 55, then divide both sides by 5 to get x = 11.

How do I check the answer?

Replace x by 11: 5(11) − 4 = 51, which is 51.

Solve 5x − 4 = 51

How to work it out

Trying values of x in 5x − 4 = 51

Questions

Similar equations