Question

Answer 1

giải hộ em câu 1+2

Answer 2

Bài 2:

a) \(\sqrt{4x+8}+\sqrt{9x+18}=5\) (ĐK: \(x\ge-2\)) 

\(\Leftrightarrow\sqrt{4\left(x+2\right)}+\sqrt{9\left(x+2\right)}=5\)

\(\Leftrightarrow2\sqrt{x+2}+3\sqrt{x+2}=5\)

\(\Leftrightarrow5\sqrt{x+2}=5\)

\(\Leftrightarrow\sqrt{x+2}=\dfrac{5}{5}\)

\(\Leftrightarrow\sqrt{x+2}=1\)

\(\Leftrightarrow x+2=1\)

\(\Leftrightarrow x=1-2\)

\(\Leftrightarrow x=-1\left(tm\right)\)

b) Ta có ham số: 

\(y=f\left(x\right)=\dfrac{1}{2}x-5\)

\(\Rightarrow f\left(0\right)=\dfrac{1}{2}\cdot0-5=0-5=-5\)

\(\Rightarrow f\left(2\right)=\dfrac{1}{2}\cdot2-5=1-5=-4\)