Question

immediately solve the question

Answer 1

given, equation

7x^8 - 3x^4 + 5 = 0

7 ( x^4 )^2 - 3x^4 + 5 = 0 ----- (1)

now put x^4 = k , in eq.(1) ,we get

7k^2 - 3k + 5 = 0

which is a quadratic polynomial ,

hence,the given equation is also quadratic.

【 hope it helps 】