Q. \(2(2x-4)=5(x-4)\)
Answer
Solve: \(2(2x-4)=5(x-4)\).
Step 1 – expand both sides:
\[
4x-8=5x-20.
\]
Step 2 – isolate \(x\): subtract \(4x\) from both sides,
\[
-8=x-20,
\]
then add 20:
\[
12=x.
\]
Final result: \(\boxed{x=12}\).
Detailed Explanation
- Write the equation:\(2(2x-4)=5(x-4)\)
- Apply the distributive property to both sides:\(2\cdot(2x)-2\cdot4 = 5\cdot x – 5\cdot4\)
So
\(4x-8 = 5x-20\)
- Isolate the variable terms on one side:Subtract \(4x\) from both sides to move \(x\)-terms to the right:
\(4x-8-4x = 5x-20-4x\)
Which simplifies to
\(-8 = x-20\)
- Solve for \(x\):Add \(20\) to both sides (inverse operation of subtraction):
\(-8+20 = x-20+20\)
\(12 = x\)
Thus \(x = 12\).
- Check the solution by substitution:Left side: \(2(2x-4)=2(2\cdot12-4)=2(24-4)=2\cdot20=40\).
Right side: \(5(x-4)=5(12-4)=5\cdot8=40\).
Both sides equal \(40\), so the solution is correct.
See full solution
FAQs
Q1: What is the solution of /2(2x-4)=5(x-4)/?
A1: Expand: /4x-8=5x-20/. Rearrange: /-8+20=5x-4x/ so /12=x/. Solution: /x=12/.
Q2: What are the steps to solve /2(2x-4)=5(x-4)/?
A2: Distribute: /4x-8=5x-20/. Move variable terms one side: subtract /4x/: /-8=x-20/. -Add 20: /12=x/. Check by substitution.
Q3: How do I check the solution /x=12/?
A3: Substitute: left /2(2(12)-4)=2(24-4)=2(20)=40/. Right /5(12-4)=5(8)=40/. Both equal 40, so /x=12/ is correct.
Q4: What common errors should I avoid?
A4: Forgetting to distribute correctly, sign errors when moving terms, and arithmetic mistakes when combining constants. -Always expand parentheses and check signs when adding/subtracting.
Q5: Could this equation have no solution or infinitely many solutions?
A5: Yes in general. If after simplifying you get a contradiction like /0=5/ there is no solution. If you get an identity like /0=0/ there are infinitely many. Here we got /x=12/, a unique solution.
Q6: Is there an alternative method besides distribution?
A6: You can divide both sides by a common factor only if it applies; here distribution is simplest. You could also expand both sides symbolically or move terms to factor, but distribution then isolating x is direct.
Q7: How does this look graphically?
A7: Each side is a line: /y=4x-8/ and /y=5x-20/. The solution is their x-coordinate intersection. Solve /4x-8=5x-20/ to get intersection at /x=12/.
Q8: Why did I add 20 to both sides?
A8: -After isolating variable terms you had /-8=x-20/. -Adding 20 cancels the constant on the right, isolating /x/ so /x=-8+20=12/.
Q9: If coefficients were fractions, any extra tips?
A9: Multiply both sides by the least common denominator first to clear fractions, then distribute and solve as usual. This reduces fraction arithmetic and sign mistakes.
Math AI tools solve different problems.
Find your favorite today!
Find your favorite today!
173,935+ happy customers
Math, Calculus, Geometry, etc.
Math, Calculus, Geometry, etc.