Question

Đề bài: Tìm x, biết :

a) \(\sqrt{25x-25}-\frac{15}{2}\sqrt{\frac{x-1}{9}}=6+\frac{3}{2}\sqrt{x-1}\)

b) \(\frac{2}{3}\sqrt{4x^2-20}+2\sqrt{\frac{x^2-5}{9}}-3\sqrt{x^2-5}=2\)

Thầy cô và bạn bè giúp em với ạ, em cảm ơn !

Answer 1

b)\(\frac{2}{3}.\sqrt{4x^2-20}+2\sqrt{\frac{x^2-5}{9}}-3\sqrt{x^2-5}=2\)

\(< =>\frac{2}{3}.\sqrt{4\left(x^2-5\right)}+2\cdot\frac{\sqrt{x^2-5}}{3}-3\sqrt{x^2-5}=2\)

\(< =>\frac{2}{3}.2\sqrt{\left(x^2-5\right)}+2\cdot\frac{\sqrt{x^2-5}}{3}-3\sqrt{x^2-5}=2\)

\(< =>\frac{4}{3}\sqrt{\left(x^2-5\right)}+\frac{2}{3}.\sqrt{x^2-5}-3\sqrt{x^2-5}=2\)

\(< =>-\sqrt{\left(x^2-5\right)}=2\)

\(< =>\sqrt{\left(x^2-5\right)}=-2\)(vô nghiệm)

Answer 2

a)\(\sqrt{25x-25}-\frac{15}{2}\sqrt{\frac{x-1}{9}}=6+\frac{3}{2}\sqrt{x-1}\)

\(< =>\sqrt{25\left(x-1\right)}-\frac{15}{2}.\frac{\sqrt{x-1}}{3}-\frac{3}{2}\sqrt{x-1}=6\)

\(< =>5\sqrt{x-1}-\frac{5}{2}.\sqrt{x-1}-\frac{3}{2}\sqrt{x-1}=6\)

\(< =>\sqrt{x-1}=6\)

\(< =>x-1=36\)

\(< =>x=37\)

vậy ...