Question

Which statement is true about the product 3(7square root of 4 + 2square root of 9? It is rational and equal to 60. It is rational and equal to 25. It is irrational and equal to 25 + 2square root of 2. It is irrational and equal to 27square root of 13.

Answer 1

It is rational, since actually

$\sqrt{4}=2,\quad\sqrt{9}=3$

so, the expression simply beco$3(7\sqrt{4} + 2\sqrt{9})=3(7\cdot2+2\cdot 3)=3(14+6)=3\cdot 20 = 60$