Question

8^3=a^9=2^b,求2a(a-b)的值

Answer 1

8^3=a^9=2^b
a=2, b=9

2×2×（2-9）=-28

Answer 2

8^3=a^9=2^b
那么
2^9=a^9=2^9
∴a=2,b=9
∴2a(a-b)=4*(-7)=-28

Answer 3

8^3=(2^3)^3=2^9;
所以a=2,b=9;
2a(a-b)=2*2(2-9)=-28