Question

(\(\frac{2121}{1212}\) + \(\frac{2121}{2020}\) + \(\frac{2121}{3030}\) + \(\frac{2121}{4242}\) ) - x = - 2015 tính đi

Answer 1

=>(\(\frac{7}{4}+\frac{21}{20}+\frac{7}{10}+\frac{1}{2}\))-x=-2015

=>(1,75+1,05+0,7+0,5)-x=-2015

=>4-x=-2015

=>x=4-(-2015)

=>x=2019

Answer 2

(\(\frac{2121}{1212}+\frac{2121}{2020}+\frac{2121}{3030}+\frac{2121}{4242}\)) - x = -2015

=> ( \(\frac{21}{12}+\frac{21}{20}+\frac{21}{30}+\frac{21}{42}\) ) - x = -2015

=> ( \(\frac{7}{4}+\frac{21}{20}+\frac{21}{30}+\frac{1}{2}\) ) - x = -2015

=> ( 1,75 + 1,05 + 0,7 + 0,5 ) - x = -2015

=> 4 - x = -2015

=> x = 4 - ( -2015 )

=> x = 4 + 2015

=> x = 2019