Answer:

Step-by-step explanation:
√a^4 is the same as:
√a × √a × √a × √a
group them as 2 pairs of
(√a × √a) × (√a × √a)
which makes
a × a
which is the same as 
2.1 x 10^10/ 7 x 10^17
= 3 x 10^-8
hope this helps and have a great day :)
Try 40x+20+4kxexponet2+4kx+k
Answer:
value of x= 4 and value of y =1.
The answer would be y= 33/a+4 I hope is helps.