Question

Can you please check this question?
What is the exact value of 7q^4 over sqrt(q^15)

A) 7 sqrt (q) over q^4
B) 7 sqrt (q) over q^3
C) 7 sqrt (q) over q^6
D) 7 sqrt (q) over q^5

I think it's A.

Answer 1

\[ \frac{7q^4}{\sqrt{q^{14} \cdot q}} = \frac{7q^4}{q^7 \cdot \sqrt{q}}= \frac{7}{q^3 \cdot \sqrt{q}}\]
but people often "rationalize" a square root in the denominator. Multiply top and bottom by sqrt{q}
\[ \frac{7\cdot \sqrt{q}}{q^3 \cdot \sqrt{q}\cdot \sqrt{q}}= \frac{7\cdot \sqrt{q}}{q^3 \cdot q}= \frac{7\cdot \sqrt{q}}{q^4}\]

Answer 2

I think you are correct. It is A