1330.11 – Square Mistake!

Tags:Problem Set 13Pre-AlgebraAlgebra Prep

Instead of finding twice the square of a number, a student whose fingers were all bandaged up found twice the square root. She got the answer 10. What is the correct answer?

Solution

Let xx be the number. Then

2x=10⇝x=25,2 \sqrt{x} = 10 \leadsto x = 25,

2x2=2⋅252=2⋅625=1250.2 x^2 = 2 \cdot 25^2 = 2 \cdot 625 = 1250.

The answer is 1250.