Question

What is the expression in simplest radical form?

3√28 + √63
A. 18√/7
B. 021√7
C. 9-√7
D. 28√9

Answer 1

`3√(28)+√(63) ~~ \begin{cases} 28=2\cdot 2\cdot 7\\ \qquad 2^2\cdot 7\\ 63= 3\cdot 3\cdot 7\\ \qquad 3^2\cdot 7 \end{cases}\qquad \implies 3√(2^2\cdot 7)+√(3^2\cdot 7) \\\\\\ 3\cdot 2√(7)+3√(7)\implies 6√(7)+3√(7)\implies 9√(7)`