Solve 3x ā 7 = ā19
The solution of 3x ā 7 = ā19 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 7 to both sides:
- 3
Divide both sides by 3:
- 4
Check: put x = -4 back into the equation.
LaTeX source of the formulas on this page
\[ 3x - 7 = -19\ \Rightarrow\ x = -4 \]
\[ 3x - 7 = -19 \]
\[ 3x - 7 + 7 = -19 + 7 \ \Rightarrow\ 3x = -12 \]
\[ \frac{3x}{3} = \frac{-12}{3} \ \Rightarrow\ x = -4 \]
\[ 3\cdot(-4) - 7 = -12 - 7 = -19 \checkmark \]Trying values of x in 3x ā 7 = ā19
| x | 3x ā 7 | Equals -19? |
|---|---|---|
| -6 | -25 | no |
| -5 | -22 | no |
| -4 | -19 | yes |
| -3 | -16 | no |
| -2 | -13 | no |
Questions
What is x in 3x ā 7 = ā19?
The solution of 3x ā 7 = ā19 is x = -4.
How do you solve 3x ā 7 = ā19?
Add 7 to both sides to get 3x = -12, then divide both sides by 3 to get x = -4.
How do I check the answer?
Replace x by -4: 3(-4) ā 7 = -19, which is -19.