Question

Giá trị của x thoả mãn ( 1 + 3 + ...... + 99)x = 2 + 4 + . + 100 là A 51/50 B 50/51 C 1 D 4/5

Answer 1

\(\left(1+3+...+99\right).x=2+4+...+100\)

\(\dfrac{\left(99+1\right).\left[\left(99-1\right):2+1\right]}{2}.x=\dfrac{\left(100+2\right).\left[\left(100-2\right):2+1\right]}{2}\)

\(2500.x=2550\)

\(x=\dfrac{2550}{2500}=\dfrac{51}{50}\)