Question

can someone do the b number question for me? pls I have exams

Answer 1

Answer:

here

Step-by-step explanation:

Given,

x2−x21=−1

Squaring on both sides

(x4+x41−2=1

x4+x41+2=3+2

(x2+x21)2=5

⟹x2+x21=5