$\frac{x+2020}{100}$ + $\frac{x+2126}{203}$ = 5 (với x∈Z)
⇒ ($\frac{x+2020}{100}$ - 3) + ($\frac{x+2126}{203}$ - 2) = 0
⇒ $\frac{x+2020-3.100}{100}$ + $\frac{x+2126-2.203}{203}$ = 0
⇒ $\frac{x+1720}{100}$ + $\frac{x+1720}{203}$ = 0
⇒( x+1720).($\frac{1}{100}$ + $\frac{1}{203}$ ) = 0 ( $\frac{1}{100}$ + $\frac{1}{203}$>0 )
⇒ x+1720 = 0
⇒ x=-1720 (t/m điều kiện)
Vậy x=-1720.
