Question

Long rationalise surds questions pls help​

Answer 1

Answer:

Noah mistakenly added 25 and 7 in denominator instead of subtracting in the third step.

Step-by-step explanation:

Noah had to rationalize the denominator of $\frac{32}{5-\sqrt{7}}$

According to him,

$\frac{32}{5-\sqrt{7} = \frac{32(5+\sqrt{7}{(5-\sqrt{7})(5+\sqrt{7}$

Solving the nominator and denominator

$= \frac{160-32\sqrt{7}}{25+5\sqrt{7}-5\sqrt{7}-7}$

Noah did correctly till this point.

In the next step he add 25 and 7 in the denominator, whereas, it should be subtracted.

Hence,

Noah mistakenly added 25 and 7 in denominator instead of subtracting in the third step.