Question

25的n+1次方-5的2n次方=120 n=

Answer 1

25的n+1次方-5的2n次方=120

25^(n+1)-5^(2n)=120

5^[2(n+1)]-5^(2n)=120

5^(2n+2)]-5^(2n)=120

5^(2n)(5^2-1)=120

5^(2n)(24)=120

5^(2n)=5

2n=1

n=1/2