Question

若A^2+2b=3 5a^2+10b=( ) -a^2-2b=( ) -3a^2-6b=( ) 若b/a=3 4b/3a

Answer 1

5a^2+10b=5*(a^2+2b)=5*3=15

-a^2-2b=-1(a^2+2b)=-1*3=-3

-3a^2-6b=-3a^2+(-3)2b=-3( a^2+2b)=-3*3=-9

若b/a=3 4b/3a=4/3*b/a=4/3*3=4

因为b/a=3,所以a/b=1/3,

a/6b=1/6*a/b=1/6*1/3=1/18