Question

Calculati in doua moduri :
a) 3/5x(1/9 + 4/9)
b) 2/3x(1/6+5/24)
c) 1/7x(7/15-3/10)

x : reprezinta inmultit!

Answer 1

a1). 3/5 * (1/9 + 4/9) = 3/5 * 5/9 = 1/3
a2). 3/5*1/9 + 3/5*4/9 = 1/15 + 4/15 = 5/15 = 1/3

b1). 2/3 * (1/6 + 5/24) = 2/3 * (4/24 + 5/24) = 2/3* 9/24 = 3/12 = 1/4
b2). 2/3*1/6 + 2/3*5/24 = 1/9 + 5/36 = (4+5) / 36 = 9/36 = 1/4

c1). 1/7 * (7/15 - 3/10) = 1/7 * (14-9)/30 = 1/7 * 5/30 = 1/42
c2). 1/7*7/15 - 1/7*3/10 = 1/15 - 3/70 = (14-9)/210 = 5/210 = 1/42