Solve 9x + 9 = −36

The solution of 9x + 9 = −36 is x = -5.

9x + 9 = -36\ \Rightarrow\ x = -5

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

The lines y = 9x + 9 and y = -36 meet at x = -5. 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.
$9x + 9 = -36$
2
Subtract 9 from both sides:
$9x + 9 - 9 = -36 - 9 \ \Rightarrow\ 9x = -45$
3
Divide both sides by 9:
$\frac{9x}{9} = \frac{-45}{9} \ \Rightarrow\ x = -5$
4
Check: put x = -5 back into the equation.
$9\cdot(-5) + 9 = -45 + 9 = -36 \checkmark$

LaTeX source of the formulas on this page

\[ 9x + 9 = -36\ \Rightarrow\ x = -5 \]
\[ 9x + 9 = -36 \]
\[ 9x + 9 - 9 = -36 - 9 \ \Rightarrow\ 9x = -45 \]
\[ \frac{9x}{9} = \frac{-45}{9} \ \Rightarrow\ x = -5 \]
\[ 9\cdot(-5) + 9 = -45 + 9 = -36 \checkmark \]

Trying values of x in 9x + 9 = −36

x	9x + 9	Equals -36?
-7	-54	no
-6	-45	no
-5	-36	yes
-4	-27	no
-3	-18	no

Questions

What is x in 9x + 9 = −36?

The solution of 9x + 9 = −36 is x = -5.

How do you solve 9x + 9 = −36?

Subtract 9 from both sides to get 9x = -45, then divide both sides by 9 to get x = -5.

How do I check the answer?

Replace x by -5: 9(-5) + 9 = -36, which is -36.

Solve 9x + 9 = −36

How to work it out

Trying values of x in 9x + 9 = −36

Questions

Similar equations