Question

tìm x

2 \(\sqrt{16x-16}\)+\(\sqrt{49x-49}\)  \(-\)  \(\sqrt{x-1}\)          =46

Answer 1

ĐKXĐ: x>=1

\(PT\Leftrightarrow8\sqrt{x-1}+7\sqrt{x-1}-\sqrt{x-1}=46\)

=>\(14\sqrt{x-1}=46\)

=>\(\sqrt{x-1}=\dfrac{23}{7}\)

=>\(x-1=\dfrac{529}{49}\)

=>\(x=\dfrac{578}{49}\)

Answer 2

2\(\sqrt{1\text{6}x-1\text{6}}\)+\(\sqrt{49x-49}\)-\(\sqrt{x-1}\)=46

<=>2.4.4\(\sqrt{x-1}\)+7.7\(\sqrt{x-1}\)-\(\sqrt{x-1}\)=46

<=> 32\(\sqrt{x-1}\)+49\(\sqrt{x-1}\)-\(\sqrt{x-1}\)=46

<=> (32+49-1)\(\sqrt{x-1}\)=46

<=> 80\(\sqrt{x-1}\)=46

<=> \(\sqrt{x-1}\)=\(\dfrac{23}{40}\)

<=> x-1=\(\dfrac{529}{1\text{6}00}\)

<=> x=\(\dfrac{2159}{1\text{6}00}\)

<=>x=1,35