Question

Calculati utilizand formulele de calcul prescurtat

Answer 1

a) (4 rad 2 - rad 30)(4 rad 2 +rad 30) - 3(rad 5 +1)^2 = 
    = 16*2 - 30 - 3(5 + 2 rad 5 + 1) = 
    = 2 - 15 - 6 rad 5 - 3 = 
    = -16 - 6 rad 5 = -2(8 + 3 rad5)
b) 4(rad 3 +1)^2 - rad 3 *(8 - rad3) - (rad 21 - rad 2)(rad 21 +  rad2) = 
    = 4(3 + 2 rad 3 + 1) - 8 rad 3 + 3 - (21 - 2) = 
    = 12 + 8 rad 3 + 4 - 8 rad 3 + 3 - 19 = 
    = 0
c) (3 rad 5 -1)^2 + rad 180 - (2 rad 3 - rad 5)(2 rad3 + rad 5) = 
    = 9*5 - 6 rad 5 + 1 + 6 rad 5 - (4*3-5) = 
    = 46 - 7 = 39
d) (rad 14 + 3)^2 + (rad 7 - 3 rad2)^2 - (rad 15 - rad 7)(rad 15 + rad 7) = 
    = 14 + 6 rad 14 + 9 + 7 - 6 rad 14 + 9*2 - (15 - 7) = 
    = 48 - 8 = 40
e) (rad 6 - 2)^2 + 2 (1+ rad 6)^2 + (rad 6 -2)(rad 6 + 2) = 
    = 6 - 4 rad 6 + 4 + 2(1 + 2 rad 6 + 6) + 6 - 4 = 
    = 10 - 4 rad 6 + 2 + 4 rad 6 + 2 = 14
f) 2(3 rad 3 + 1)^2 + 3(rad 3 - 2)^2 - (11 - rad 15)(11 + rad 15) = 
   = 2(9*3 + 6 rad 3 + 1) + 3(3 - 4 rad 3 + 4) - (121 - 15) = 
   = 2(28 + 6 rad3) + 3(7 - 4 rad3) - 106 = 
   = 56 + 12 rad 3 + 21 - 12 rad 3 - 106 = -29