Question

a)suma a trei nr consecutive este 33.determinati nr
b)suma a cinci nr naturale consecutive este 260.determinati nr
c)suma a trei nr naturale pare consecutive este 222.determinati nr

Answer 1

3x+3=33 x=10 nr consecutiv 10 11 12 5x+1+2+3+4=260 5x=250 x=50 nr 50 51 52 53 54 3x+2+4=222 3x=222-6 3x=216 x=72 nr 72 74 76

Answer 2

a) a + b + c = 33

b = a + 1

c = b + 1 = a + 2

a + a + 1 + a + 2 = 33

3a + 3 = 33 | -3

3a = 30 | : 3

a = 10 = > b = 11 , c = 12

b) a + b + c + d + e = 260

b = a + 1

c = b + 1 = a + 2

d = c + 1 = a + 3

e = d + 1 = a + 4

a + a + 1 + a + 2 + a + 3 + a + 4 = 260

5a + 10 = 260 | - 10

5a = 250 | : 5

a = 50 = > b = 51 , c = 52 , d = 53 , e = 54

c) a + b + c = 222

a = nr par

b = a + 2

c = b + 2 = a + 4

a + a + 2 + a + 4 = 222

3a + 6 = 222 | - 6

3a = 216 | : 3

a = 72 = > b = 74 , c = 76