Question

如果a+4=﹣3b求3a×27b的值

Answer 1

a-4=-3b

a+3b=4

3^a*27^b

=3^a*3^3b

=3^(a+3b)=3^4=81 (20/3)^a×(8/15)^b×(9/16)^c=4

[(2^2×5)/3]^a×[(2^3)/(3×5)]^b×[(3^2)/(2^4)]^c=4

[2^(2a+3b)×3^2c×5^a]/[2^4c×3^(a+b)×5^b]=4

2^(2a+3b-4c)×3^(2c-a-b)×5^(a-b)=2^2

∴2a+3b-4c=2

2c-a-b=0

a-b=0

a=b=c=2