Question

nu stiu cum sa-l fac.M-am chinuit mult...

Answer 1

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Answer 2

a)

a · b = 2 / 15 si a · c = 11 / 75

a · ( b + c ) = a · b + a · c = 2 / 15 + 11 / 75 = 10 / 75 + 11 / 75 = 21 / 75 = 7 / 25

b)

a · c = 7 / 36 si b · c = 19 / 48

c · ( b - a ) = b · c - a · c = 19 / 48 - 7 / 36 = ( 19 × 3) / 144 - ( 7 × 4 ) / 144 =

57 / 144 - 28 / 144 = 29 / 144

cmmmc al numitorilor ( 48 si 36 ) = 2⁴ x 3² = 16 x 9 = 144

48 = 2 ⁴ x 3

36 = 2² x 3²

c)

a = 5 / 6 ; b + c = 7 / 20 si c - d = 1 / 24

a · b + 2 · a · c - c · d = a · b + a · c + a · c - c · d = a · ( b + c ) + a · ( c - d ) =

5 / 6 · 7 / 20 + 5 / 6 · 1 / 24 = 7 / 24 + 5 / 144 = 42 / 144 + 5 / 144 = 47 / 144