tìm a

M

manhnguyen0164

Ta có : $\dfrac{a+51}{49}+\dfrac{a+27}{73}+\dfrac{a+31}{69}+3=0$

$\iff (\dfrac{a+51}{49}+1)+(\dfrac{a+27}{73}+1)+(\dfrac{a+31}{69}+1)=0$

$\iff \dfrac{a+100}{49}+\dfrac{a+100}{73}+\dfrac{a+100}{69}=0$

$\iff (a+100)(\dfrac{1}{49}+\dfrac{1}{73}+\dfrac{1}{69})=0$

$\iff a+100=0$ (do $\dfrac{1}{49}+\dfrac{1}{73}+\dfrac{1}{69}\ne0$)

$\iff a=-100$
 
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