Solve 11x + 7 = 40
The solution of 11x + 7 = 40 is x = 3.
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.
- 2
Subtract 7 from both sides:
- 3
Divide both sides by 11:
- 4
Check: put x = 3 back into the equation.
LaTeX source of the formulas on this page
\[ 11x + 7 = 40\ \Rightarrow\ x = 3 \]
\[ 11x + 7 = 40 \]
\[ 11x + 7 - 7 = 40 - 7 \ \Rightarrow\ 11x = 33 \]
\[ \frac{11x}{11} = \frac{33}{11} \ \Rightarrow\ x = 3 \]
\[ 11\cdot3 + 7 = 33 + 7 = 40 \checkmark \]Trying values of x in 11x + 7 = 40
| x | 11x + 7 | Equals 40? |
|---|---|---|
| 1 | 18 | no |
| 2 | 29 | no |
| 3 | 40 | yes |
| 4 | 51 | no |
| 5 | 62 | no |
Questions
What is x in 11x + 7 = 40?
The solution of 11x + 7 = 40 is x = 3.
How do you solve 11x + 7 = 40?
Subtract 7 from both sides to get 11x = 33, then divide both sides by 11 to get x = 3.
How do I check the answer?
Replace x by 3: 11(3) + 7 = 40, which is 40.