ta có:a/2=2b  =>a=4b

=> (9/8).a=9/8. 4b=36/8 .b =kb

=>k=36/8.b:b=36/8=9/2=4,5
 

Chắc là \(k=\frac{9}{2}\)

\(\frac{1}{2}a=2b\Rightarrow a=4b\Rightarrow kb=\frac{9}{8}a=\frac{9}{8}.4b=\frac{9}{2}b\Rightarrow k=\frac{9}{2}\)

Ta có: \(\frac{1}{2}a=2b\Rightarrow a=4b\)

\(\frac{9}{8}a=kb\)

\(\Rightarrow\frac{9}{8}.4.b=kb\)

\(\Rightarrow\frac{36}{8}b=kb\)

\(\Rightarrow k=\frac{36}{8}\)

Vậy \(k=\frac{36}{8}\)

4,5

\(\frac{1}{2}a=2b\Rightarrow\frac{1}{8}a=\frac{1}{2}b=>\frac{9}{8}a=\frac{9}{2}b=>k=\frac{9}{2}\)

1/2 của a=2b

=>a/2=2b=>a=4b

=>\(\frac{9}{8}.a=\frac{9}{8}.4b=\frac{36}{8}.b=kb=>k=\frac{36}{8}.b:b=\frac{36}{8}=\frac{9}{2}=4,5\)

vậy k=4,5

tick nha

\(\frac{1}{2}a=2b\Leftrightarrow a=4b\)

\(\frac{9}{8}a=\frac{9}{8}.4b=\frac{9}{2}b=kb\Leftrightarrow k=\frac{9}{2}\)

vì 1/2 của a bằng 2b. suy ra a=4b

mà 9/8=kb suy ra  k=4*9/8=9/2