Simplifying roots, step by step
√(64x²) is 8x, and the tempting wrong answers each take half of it out and leave the other half behind.
The question
Check this line: √(96x²) + √(6x²) = 5x. Which is correct?
Check this line: √(96x²) + √(6x²) = 5x. Which is correct?
√(96x²) + √(6x²)
√(96x²) + √(6x²)=4x√6 + x√6
√(96x²) + √(6x²)=4x√6 + x√6
√(96x²) + √(6x²)=5x√6
√(96x²) + √(6x²)=5x√6
they wrote:5x
- Do not check by reading their line. Somebody else's working is the most persuasive thing on the page, and rereading it is how you end up agreeing with it — do the step yourself first, then compare.
- On your own, and writing the step nobody writes down: √(96x²) + √(6x²) becomes 4x√6 + x√6.
- Tidy that up and it is 5x√6.
- Now compare. They wrote 5x, and the part that would not come out was dropped — so the correct answer is 5x√6.
How it works.
- 01
Do not check by reading their line. Somebody else's working is the most persuasive thing on the page, and rereading it is how you end up agreeing with it — do the step yourself first, then compare.
- 02
On your own, and writing the step nobody writes down: √(96x²) + √(6x²) becomes 4x√6 + x√6.
- 03
Tidy that up and it is 5x√6.
- 04
Now compare. They wrote 5x, and the part that would not come out was dropped — so the correct answer is 5x√6.