Solve 7x − 9 = 103

The solution of 7x − 9 = 103 is x = 16.

7x - 9 = 103\ \Rightarrow\ x = 16

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

The lines y = 7x − 9 and y = 103 meet at x = 16. 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.
$7x - 9 = 103$
2
Add 9 to both sides:
$7x - 9 + 9 = 103 + 9 \ \Rightarrow\ 7x = 112$
3
Divide both sides by 7:
$\frac{7x}{7} = \frac{112}{7} \ \Rightarrow\ x = 16$
4
Check: put x = 16 back into the equation.
$7\cdot16 - 9 = 112 - 9 = 103 \checkmark$

LaTeX source of the formulas on this page

\[ 7x - 9 = 103\ \Rightarrow\ x = 16 \]
\[ 7x - 9 = 103 \]
\[ 7x - 9 + 9 = 103 + 9 \ \Rightarrow\ 7x = 112 \]
\[ \frac{7x}{7} = \frac{112}{7} \ \Rightarrow\ x = 16 \]
\[ 7\cdot16 - 9 = 112 - 9 = 103 \checkmark \]

Trying values of x in 7x − 9 = 103

x	7x − 9	Equals 103?
14	89	no
15	96	no
16	103	yes
17	110	no
18	117	no

Questions

What is x in 7x − 9 = 103?

The solution of 7x − 9 = 103 is x = 16.

How do you solve 7x − 9 = 103?

Add 9 to both sides to get 7x = 112, then divide both sides by 7 to get x = 16.

How do I check the answer?

Replace x by 16: 7(16) − 9 = 103, which is 103.

Solve 7x − 9 = 103

How to work it out

Trying values of x in 7x − 9 = 103

Questions

Similar equations