Question

va rogggg............​

Answer 1

Răspuns:

Explicație pas cu pas:

2a5 divizibil cu 9 ⇒ suma cifrelor trebuie sa fie divizibila cu 9 ⇒ a = 2

⇒ 2a5 = 225

225/35 = 36/x

produsul mezilor  = produsul extremilor

225*x = 36*35

225*x = 1260

x = 1260/225 = 252/45 = 28/5

_______________

2^2019 + 2^2020 + 2^2021 = 2^2019*(1 + 2 + 2^2) = 7*2^2019

32^404 = (2^5)^404 = 2^2020

7*2^2019/x = 2^2020/0.5

0,5*7*2^2019 = 2^2020*x

3,5*2^2019 = 2^2020*x

x = 3,5*2^2019/2^2020 = 3,5/2 = 1,75

_______________

1 + 2 + 3 + ... + 102 = 102*103/2 = 51*103

0,(3) = 3/9 = 1/3

x/51*103 = (1/3)/103

103*x = 51*103*1/3 = 17*103

x = 17*103/103 = 17

_______________

x/y = 5/13

x/5 = y/13 = k

x = 5k

y = 13k

(x + y)/y = (5k + 13k)/13k = 18k/13k = 18/13

x/(y + x) = 5k/(13k + 5k) = 5k/18k = 5/18

(y - x)/x = (13k - 5k)/5k = 8k/5k = 8/5