Question

Afla numerele necunoscute :
a) (a-80) ×2-324=32
b) (100- b:3)×5=250
c) ( c:9:3)×2=20


De clasa a 4-a

Answer 1

a)

( a - 80 ) × 2 - 324 = 32

( a - 80 ) × 2 = 32 + 324

( a - 80 ) × 2 = 356

a - 80 = 356 : 2

a - 80 = 178

a = 178 + 80

a = 258

b)

( 100 - b : 3 ) × 5 = 250

100 - b : 3 = 250 : 5

100 - b : 3 = 50

b : 3 = 100 - 50

b : 3 = 50

b = 50 × 3

b = 150

c)

( c : 9 : 3 ) × 2 = 20

c : 9 : 3 = 20 : 2

c : 9 : 3 = 10

c : 9 = 10 × 3

c : 9 = 30

c = 30 × 9

c = 270