Solve 9x + 7 = −65

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

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

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The lines y = 9x + 7 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 addition, then the multiplication.
$9x + 7 = -65$
2
Subtract 7 from both sides:
$9x + 7 - 7 = -65 - 7 \ \Rightarrow\ 9x = -72$
3
Divide both sides by 9:
$\frac{9x}{9} = \frac{-72}{9} \ \Rightarrow\ x = -8$
4
Check: put x = -8 back into the equation.
$9\cdot(-8) + 7 = -72 + 7 = -65 \checkmark$

LaTeX source of the formulas on this page

\[ 9x + 7 = -65\ \Rightarrow\ x = -8 \]
\[ 9x + 7 = -65 \]
\[ 9x + 7 - 7 = -65 - 7 \ \Rightarrow\ 9x = -72 \]
\[ \frac{9x}{9} = \frac{-72}{9} \ \Rightarrow\ x = -8 \]
\[ 9\cdot(-8) + 7 = -72 + 7 = -65 \checkmark \]

Trying values of x in 9x + 7 = −65

x	9x + 7	Equals -65?
-10	-83	no
-9	-74	no
-8	-65	yes
-7	-56	no
-6	-47	no

Questions

What is x in 9x + 7 = −65?

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

How do you solve 9x + 7 = −65?

Subtract 7 from both sides to get 9x = -72, then divide both sides by 9 to get x = -8.

How do I check the answer?

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

Solve 9x + 7 = −65

How to work it out

Trying values of x in 9x + 7 = −65

Questions

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