Question

tim y

( 1/ 24x25 + 1/ 25x26 + ..... + 1/ 29x30 ) x 120 + y : 1/3 = -4

Answer 1

(1/24x25 + 1/25x26 + ... + 1/29x30) x 120 + y : 1/3 = -4

(1/24 - 1/25 + 1/25 - 1/26 + ... + 1/29 - 1/30) x 120 + y x 3 = -4

(1/24 - 1/30) x 120 + y x 3 = -4

1/120 x 120 + y x 3 = -4

=> 1 + y x 3 = -4

=> y x 3 = -4 - 1

=> y x 3 = -5

=> y = -5/3

Vậy x = -5/3

Ủng hộ mk nha ^_-

Answer 2

(1/24x25 + 1/25x26 + ... + 1/29x30) x 120 + y : 1/3 = -4

(1/24 - 1/25 + 1/25 - 1/26 + ... + 1/29 - 1/30) x 120 + y x 3 = -4

(1/24 - 1/30) x 120 + y x 3 = -4

1/120 x 120 + y x 3 = -4

=> 1 + y x 3 = -4

=> y x 3 = -4 - 1

=> y x 3 = -5

=> y = -5/3

Vậy x = -5/3

T_I_C_K mk nha