Question

Afla nr necunoscut
(100-b:3)×5=490
(C:9:3)×4=20

Answer 1

(100-b:3)×5=490

100 -b: 3 = 490 : 5

100 - b : 3 = 98

b : 3 = 100 - 98

b : 3 = 2

b = 3×2

b = 6


(C:9:3)×4=20

c : 9 : 3 = 20 : 4

c : 9 : 3 = 5

c : 9 = 5 × 3

c : 9 = 15

c = 15 × 9

c = 135