Solve 7x − 9 = 61

The solution of 7x − 9 = 61 is x = 10.

7x - 9 = 61\ \Rightarrow\ x = 10

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The lines y = 7x − 9 and y = 61 meet at x = 10. 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.
$7x - 9 = 61$
2
Add 9 to both sides:
$7x - 9 + 9 = 61 + 9 \ \Rightarrow\ 7x = 70$
3
Divide both sides by 7:
$\frac{7x}{7} = \frac{70}{7} \ \Rightarrow\ x = 10$
4
Check: put x = 10 back into the equation.
$7\cdot10 - 9 = 70 - 9 = 61 \checkmark$

LaTeX source of the formulas on this page

\[ 7x - 9 = 61\ \Rightarrow\ x = 10 \]
\[ 7x - 9 = 61 \]
\[ 7x - 9 + 9 = 61 + 9 \ \Rightarrow\ 7x = 70 \]
\[ \frac{7x}{7} = \frac{70}{7} \ \Rightarrow\ x = 10 \]
\[ 7\cdot10 - 9 = 70 - 9 = 61 \checkmark \]

Trying values of x in 7x − 9 = 61

x	7x − 9	Equals 61?
8	47	no
9	54	no
10	61	yes
11	68	no
12	75	no

Questions

What is x in 7x − 9 = 61?

The solution of 7x − 9 = 61 is x = 10.

How do you solve 7x − 9 = 61?

Add 9 to both sides to get 7x = 70, then divide both sides by 7 to get x = 10.

How do I check the answer?

Replace x by 10: 7(10) − 9 = 61, which is 61.

Solve 7x − 9 = 61

How to work it out

Trying values of x in 7x − 9 = 61

Questions

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