Question

.若n为正整数,且x的2n次方=4,求（5x的2n次方）²-7（x²)的2n次方的值

Answer 1

（5x的2n次方）²-7（x²)的2n次方=5^2*（x^2n)^2-7*(x^2n)^2

=25*4^2-74^2

=25*16-7*16

=16*(25-7)

=16*18

=288