Question

已知2的x+1次方+2的x+2次方+2的x+3次方=448,求x的值

Answer 1

2^(x+1)+2^(x+2)+2^(x+3)=448

2^(x+2)(1/2+1+2)=448

2^(x+2）=128

2^(x+2)=2^7

x+2=7

x=5