Solve 12x + 8 = −100

The solution of 12x + 8 = −100 is x = -9.

12x + 8 = -100\ \Rightarrow\ x = -9

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

The lines y = 12x + 8 and y = -100 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 addition, then the multiplication.
$12x + 8 = -100$
2
Subtract 8 from both sides:
$12x + 8 - 8 = -100 - 8 \ \Rightarrow\ 12x = -108$
3
Divide both sides by 12:
$\frac{12x}{12} = \frac{-108}{12} \ \Rightarrow\ x = -9$
4
Check: put x = -9 back into the equation.
$12\cdot(-9) + 8 = -108 + 8 = -100 \checkmark$

LaTeX source of the formulas on this page

\[ 12x + 8 = -100\ \Rightarrow\ x = -9 \]
\[ 12x + 8 = -100 \]
\[ 12x + 8 - 8 = -100 - 8 \ \Rightarrow\ 12x = -108 \]
\[ \frac{12x}{12} = \frac{-108}{12} \ \Rightarrow\ x = -9 \]
\[ 12\cdot(-9) + 8 = -108 + 8 = -100 \checkmark \]

Trying values of x in 12x + 8 = −100

x	12x + 8	Equals -100?
-11	-124	no
-10	-112	no
-9	-100	yes
-8	-88	no
-7	-76	no

Questions

What is x in 12x + 8 = −100?

The solution of 12x + 8 = −100 is x = -9.

How do you solve 12x + 8 = −100?

Subtract 8 from both sides to get 12x = -108, then divide both sides by 12 to get x = -9.

How do I check the answer?

Replace x by -9: 12(-9) + 8 = -100, which is -100.

Solve 12x + 8 = −100

How to work it out

Trying values of x in 12x + 8 = −100

Questions

Similar equations