Question

Simplify 4√4 - 4√8+ √98

Answer 1

`\bf 4√(4)-4√(8)+√(98)~~\begin{cases}4=2\cdot 2\\\qquad 2^2\\8=2\cdot 2\cdot 2\\\qquad 2^2\cdot 2\\98=2\cdot 7\cdot 7\\\qquad 2\cdot 7^2\end{cases}\implies 4√(2^2)-4√(2^2\cdot 2)+√(2\cdot 7^2)\\\\\\(4\cdot 2)-(4\cdot 2)√(2)+7√(2)\implies 8\stackrel{like-terms}{-8√(2)+7√(2)}\implies 8-√(2)`

Answer 2

8 -
`√(2)`

Or the decimal version 6.58578643

Explanation: