Problem Solving (PS) | Re: If a and b represent positive real numbers and (a^4+b^2)^2=198 and a^8

simplify

(a4+b2)2=198(a4+b2)2=198
a8+b^4+2a^4*b^2 = 198
given
a8+b4=36

2a^4*b^2 = 198-36
a^4*b^2= 81
square both sides
a^2*b=9
again square
a√b=3
IMO B

If a and b represent positive real numbers and (a4+b2)2=198(a4+b2)2=198 and a8+b4=36, what is the value of ab‾√ab?

A. 2.6
B. 3.0
C. 3.4
D. 4.0
E. 4.2

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