WordGPT

Solve 12x + 9 = 129

The solution of 12x + 9 = 129 is x = 10.

Explain it step by step in chatMake a short video of it
The lines y = 12x + 9 and y = 129 meet at x = 10468101214166080100120140160180200x = 10y = 12x + 9y = 129
The lines y = 12x + 9 and y = 129 meet at x = 10. The solution of the equation is the x-coordinate of the point where the two sides are equal.

How to work it out

  1. 1

    The goal is to get x alone. Undo the operations in the opposite order: first the addition, then the multiplication.

    12x+9=12912x + 9 = 129
  2. 2

    Subtract 9 from both sides:

    12x+9−9=129−9 ⇒ 12x=12012x + 9 - 9 = 129 - 9 \ \Rightarrow\ 12x = 120
  3. 3

    Divide both sides by 12:

    12x12=12012 ⇒ x=10\frac{12x}{12} = \frac{120}{12} \ \Rightarrow\ x = 10
  4. 4

    Check: put x = 10 back into the equation.

    12⋅10+9=120+9=129✓12\cdot10 + 9 = 120 + 9 = 129 \checkmark
LaTeX source of the formulas on this page
\[ 12x + 9 = 129\ \Rightarrow\ x = 10 \]
\[ 12x + 9 = 129 \]
\[ 12x + 9 - 9 = 129 - 9 \ \Rightarrow\ 12x = 120 \]
\[ \frac{12x}{12} = \frac{120}{12} \ \Rightarrow\ x = 10 \]
\[ 12\cdot10 + 9 = 120 + 9 = 129 \checkmark \]

Trying values of x in 12x + 9 = 129

x12x + 9Equals 129?
8105no
9117no
10129yes
11141no
12153no

Questions

What is x in 12x + 9 = 129?

The solution of 12x + 9 = 129 is x = 10.

How do you solve 12x + 9 = 129?

Subtract 9 from both sides to get 12x = 120, then divide both sides by 12 to get x = 10.

How do I check the answer?

Replace x by 10: 12(10) + 9 = 129, which is 129.

Similar equations

    Solve 12x + 9 = 129: x = 10 (steps and check) | WordGPT