Solve 7x ā 2 = ā30
The solution of 7x ā 2 = ā30 is x = -4.
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.
- 2
Add 2 to both sides:
- 3
Divide both sides by 7:
- 4
Check: put x = -4 back into the equation.
LaTeX source of the formulas on this page
\[ 7x - 2 = -30\ \Rightarrow\ x = -4 \]
\[ 7x - 2 = -30 \]
\[ 7x - 2 + 2 = -30 + 2 \ \Rightarrow\ 7x = -28 \]
\[ \frac{7x}{7} = \frac{-28}{7} \ \Rightarrow\ x = -4 \]
\[ 7\cdot(-4) - 2 = -28 - 2 = -30 \checkmark \]Trying values of x in 7x ā 2 = ā30
| x | 7x ā 2 | Equals -30? |
|---|---|---|
| -6 | -44 | no |
| -5 | -37 | no |
| -4 | -30 | yes |
| -3 | -23 | no |
| -2 | -16 | no |
Questions
What is x in 7x ā 2 = ā30?
The solution of 7x ā 2 = ā30 is x = -4.
How do you solve 7x ā 2 = ā30?
Add 2 to both sides to get 7x = -28, then divide both sides by 7 to get x = -4.
How do I check the answer?
Replace x by -4: 7(-4) ā 2 = -30, which is -30.