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Solve 12x + 7 = 115

The solution of 12x + 7 = 115 is x = 9.

The lines y = 12x + 7 and y = 115 meet at x = 9468101214406080100120140160180200x = 9y = 12x + 7y = 115
The lines y = 12x + 7 and y = 115 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. 1

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

    12x+7=11512x + 7 = 115
  2. 2

    Subtract 7 from both sides:

    12x+7−7=115−7 ⇒ 12x=10812x + 7 - 7 = 115 - 7 \ \Rightarrow\ 12x = 108
  3. 3

    Divide both sides by 12:

    12x12=10812 ⇒ x=9\frac{12x}{12} = \frac{108}{12} \ \Rightarrow\ x = 9
  4. 4

    Check: put x = 9 back into the equation.

    12⋅9+7=108+7=115✓12\cdot9 + 7 = 108 + 7 = 115 \checkmark
LaTeX source of the formulas on this page
\[ 12x + 7 = 115\ \Rightarrow\ x = 9 \]
\[ 12x + 7 = 115 \]
\[ 12x + 7 - 7 = 115 - 7 \ \Rightarrow\ 12x = 108 \]
\[ \frac{12x}{12} = \frac{108}{12} \ \Rightarrow\ x = 9 \]
\[ 12\cdot9 + 7 = 108 + 7 = 115 \checkmark \]

Trying values of x in 12x + 7 = 115

x12x + 7Equals 115?
791no
8103no
9115yes
10127no
11139no

Questions

What is x in 12x + 7 = 115?

The solution of 12x + 7 = 115 is x = 9.

How do you solve 12x + 7 = 115?

Subtract 7 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) + 7 = 115, which is 115.

Similar equations

    Solve 12x + 7 = 115: x = 9 (steps and check) | WordGPT