Question

afla nr necunoscute : a) (a-80)×2-146=24 b) (100-b:3)×5 = 490 c) (c:9:3)×4=20

Answer 1

Răspuns

Explicație pas cu pas:

a) ( a - 80 ) x 2 - 146 =24

( a - 80) x 2 = 24 + 146

( a + 80 ) x 2 = 170

a + 80 = 170 : 2

a + 80 = 85

a = 85+80

a = 165

b) ( 100 -b : 3) x 5 = 490

(100 - b : 3= 490 : 5

100 - b : 3 = 98

b : 3 = 100 - 98

b : 3 = 2

b = 2 x 3

b = 6

c) ) ( c : 9 : 3 ) x 4 =20

c : 9 ; 3 = 20 : 4

c : 9 : 3 = 5

c ; 9 = 5 x 3

c ; 9 = 15

c = 15 x 9

c = 135