Solve 9x − 10 = −91

The solution of 9x − 10 = −91 is x = -9.

9x - 10 = -91\ \Rightarrow\ x = -9

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

The lines y = 9x − 10 and y = -91 meet at x = -9. 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.
$9x - 10 = -91$
2
Add 10 to both sides:
$9x - 10 + 10 = -91 + 10 \ \Rightarrow\ 9x = -81$
3
Divide both sides by 9:
$\frac{9x}{9} = \frac{-81}{9} \ \Rightarrow\ x = -9$
4
Check: put x = -9 back into the equation.
$9\cdot(-9) - 10 = -81 - 10 = -91 \checkmark$

LaTeX source of the formulas on this page

\[ 9x - 10 = -91\ \Rightarrow\ x = -9 \]
\[ 9x - 10 = -91 \]
\[ 9x - 10 + 10 = -91 + 10 \ \Rightarrow\ 9x = -81 \]
\[ \frac{9x}{9} = \frac{-81}{9} \ \Rightarrow\ x = -9 \]
\[ 9\cdot(-9) - 10 = -81 - 10 = -91 \checkmark \]

Trying values of x in 9x − 10 = −91

x	9x − 10	Equals -91?
-11	-109	no
-10	-100	no
-9	-91	yes
-8	-82	no
-7	-73	no

Questions

What is x in 9x − 10 = −91?

The solution of 9x − 10 = −91 is x = -9.

How do you solve 9x − 10 = −91?

Add 10 to both sides to get 9x = -81, then divide both sides by 9 to get x = -9.

How do I check the answer?

Replace x by -9: 9(-9) − 10 = -91, which is -91.

Solve 9x − 10 = −91

How to work it out

Trying values of x in 9x − 10 = −91

Questions

Similar equations