Question

Answer 1

4:

Độ dài cạnh của miếng bìa là 

\(\sqrt{64}=8\left(cm\right)\)

3:

a: \(\dfrac{2}{3}+x=\dfrac{3}{5}\)

=>\(x=\dfrac{3}{5}-\dfrac{2}{3}\)

=>\(x=\dfrac{9-10}{15}=-\dfrac{1}{15}\)

b: 6^x:2^x+1=162

=>\(\dfrac{2^x\cdot3^x}{2^x\cdot2}=162\)

=>\(\dfrac{3^x}{2}=162\)

=>\(3^x=324\)

=>\(x=log_3324\)

2:

a: \(\dfrac{17}{25}+\dfrac{2}{35}-\dfrac{42}{25}+\dfrac{33}{35}\)

\(=\dfrac{2}{35}+\dfrac{33}{35}+\dfrac{17}{25}-\dfrac{42}{25}\)

=1-1

=0

b: \(\dfrac{11}{2}\cdot3\dfrac{2}{5}-1\dfrac{2}{5}\cdot\dfrac{11}{2}\)

\(=\dfrac{11}{2}\left(3+\dfrac{2}{5}-1-\dfrac{2}{5}\right)\)

\(=\dfrac{11}{2}\cdot2=11\)