Question

please give me the answers please give me the answers please give me the answers please don't spam it's very urgent ​

Answer 1

13. By rationalizing,

$5 \sqrt{7} + 5 \sqrt{5} \div 2$

14. It's a rational number

15. By simplifying:

$70 \sqrt{2}$

SORRY I CAN'T GIVE THE EXPLAINATION.

But still hoping that these will help you.