a) \(\sqrt{4\left(1-x\right)^2}-12=0\)
\(\sqrt{4\left(1-x\right)^2}=0+12\)
\(\sqrt{4\left(1-x\right)^2}=12\)
\(\left[\sqrt{4\left(1-x\right)^2}\right]^2=12^2\)
\(4-8x+4x^2=144\)
\(\Rightarrow\orbr{\begin{cases}x=7\\x=-5\end{cases}}\)
b) \(\sqrt{4x^2-12x+9}=5\)
\(\left(\sqrt{4x^2-12x+9}\right)^2=5^2\)
\(4x^2-12x+9=25\)
\(\Rightarrow\orbr{\begin{cases}x=4\\x=-1\end{cases}}\)
BÀI 1:
a)
\(A=4\sqrt{3}-2\sqrt{3}+1-\sqrt{3}\)
=> \(A=\sqrt{3}+1\)
b)
\(B=\frac{\sqrt{5}\left(\sqrt{3}-1\right)}{\sqrt{3}-1}-\frac{\sqrt{5}\left(\sqrt{5}-2\right)}{2\left(\sqrt{5}-2\right)}\)
=> \(B=\sqrt{5}-\frac{\sqrt{5}}{2}\)
=> \(B=\frac{\sqrt{5}}{2}\)