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Solving
3x - 4 = 5
Add 4 to both sides
3x - 4 + 4 = 5 + 4
3x = 9
x = 9/3
x = 3
Equivalent expressions are:
1. 3x = 9
2. 3x - 4 + 4 = 5 + 4
3. 4 = 5 - 3x
If you're confused about the last one
Solving
−4=5−3x
Step 1: Simplify both sides of the equation.
−4=5−3x
−4=5+−3x
−4=−3x+5
Step 2: Flip the equation.
−3x+5=−4
Step 3: Subtract 5 from both sides.
−3x+5−5=−4−5
−3x=−9
Step 4: Divide both sides by -3.
−3x/−3 = −9/−3
x=3 (Still the same answer)