Solve 7x − 9 = −65

The solution of 7x − 9 = −65 is x = -8.

7x - 9 = -65\ \Rightarrow\ x = -8

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The lines y = 7x − 9 and y = -65 meet at x = -8. 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.
$7x - 9 = -65$
2
Add 9 to both sides:
$7x - 9 + 9 = -65 + 9 \ \Rightarrow\ 7x = -56$
3
Divide both sides by 7:
$\frac{7x}{7} = \frac{-56}{7} \ \Rightarrow\ x = -8$
4
Check: put x = -8 back into the equation.
$7\cdot(-8) - 9 = -56 - 9 = -65 \checkmark$

LaTeX source of the formulas on this page

\[ 7x - 9 = -65\ \Rightarrow\ x = -8 \]
\[ 7x - 9 = -65 \]
\[ 7x - 9 + 9 = -65 + 9 \ \Rightarrow\ 7x = -56 \]
\[ \frac{7x}{7} = \frac{-56}{7} \ \Rightarrow\ x = -8 \]
\[ 7\cdot(-8) - 9 = -56 - 9 = -65 \checkmark \]

Trying values of x in 7x − 9 = −65

x	7x − 9	Equals -65?
-10	-79	no
-9	-72	no
-8	-65	yes
-7	-58	no
-6	-51	no

Questions

What is x in 7x − 9 = −65?

The solution of 7x − 9 = −65 is x = -8.

How do you solve 7x − 9 = −65?

Add 9 to both sides to get 7x = -56, then divide both sides by 7 to get x = -8.

How do I check the answer?

Replace x by -8: 7(-8) − 9 = -65, which is -65.

Solve 7x − 9 = −65

How to work it out

Trying values of x in 7x − 9 = −65

Questions

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