C = 98 + 96 + 94 + .. + 4 + 2 - 97 - 95 - 93 - .. - 3
= (98 + 96 + 94 + ... + 4 + 2) - (97 + 95 + 93 + ... + 3)
= 49 . 100 : 2 - 48.100 : 2
= 49.50 - 48.50
= 50.(49 - 48)
= 50 . 1
= 50
Vậy C = 50
\(C=98+96+94+...+4+2-97-95-93-...-3\)
\(=\left(98+2\right).49:2-\left(97+95+93+...+3\right)\)
\(=49.50-\left(97+3\right).48:2=49.50+48.50=\left(49+48\right).50=97.50=4850\)
ơ mình nhầm
\(=\left(49-48\right)50=50\)
nha bạn
\(C=98+96+94+...+4+2-97-95-93-...-3\)
\(=\left(98+96+94+...+4+2\right)-\left(97+95+93+...+3\right)\)
\(=49.100:2-48.100:2\)
\(=49.50-48.50\)
\(=50.\left(49-48\right)\)
\(=50.1\)
\(=50\)