Question

dau 20 puncte daca rezolvati corect !!
determinati nr a, b,c invers proportionale cu nr 1,5 ; 2,5 ; 3,5 . x+2y+3z=244

Answer 1

{a,b,c} i.p {1,5 ; 2,5 ; 3,5}

a+2b+3c=244

a supra 1 supra 1,5 = b supra 1 supra 2,5 = c supra 1 supra 3,5 = K

a supra 1 supra 15/10 = b supra 1 supra 25/10 = c supra 1 supra 35/10 = K

a supra 1 supra 3/2 = b supra 1 supra 5/2 = c supra 1 supra 7/2 = K

a=2K/3

b=2K/5

c=2K/7

2K/3+2*2K/5+3*2K/7=244

2K/3+4K/5+6K/7=244

70K+84K+90K( 2K/3 amplificam cu 35, 4K/5 amplificam cu 21, 6K/7 amplificam cu 15)=244 (care il amplificam cu 105)

70K+84K+90K=25620
244K=25620/244

K=105

a=2*105/3=70

b=2*105/5=42

c=2*105/7=30