Question

若n为正整数,且x的二n次方=5,求(3x的3n次方)的2次方-4(x的2次方)的2n次方的值

Answer 1

3(x的3n次方)的2次方-4(x的2次方)的2n次方
=3(x的6n次方)-4(x的4n次方)
=3(x的2n次方)的3次方-4(x的2n次方)的2次方
=3*5的3次方-4*5的2次方
=3*125-4*25
=375-100
=275

Answer 2

（3x的3n次方）的2次方-4（x的2次方）的2n次方
=9x的6n次方-4x的4n次方
=9(x的2n次方）的3次方-4（x的2n次方）的2次方 x的2n次方=7
=9*7³-4*7²
=7²(9*7-4)
=49*59
=(50-1)(60-1)
=3000-60-50+1
=2891