Răspuns:
15.
(x,42) i.p. (1/7,3)
x•1/7=42•3
x•1/7= 126
x=126×7
x=882
* /= linie de fractie
•= ori , semnul inmultirii ×
16.
(x,y,z)i.p.(3,6,9)
x•3=y•6=z•9= k
=> x=k/3
y=k/6
z=k/9
a) x+y+z=28
k/3+k/6+k/9=28 |•18
6k+3k+2k=504
11k=504
k=504/11
[tex]x = \frac{ \frac{504}{11} }{3} = \frac{168}{11} \\ y = \frac{ \frac{504}{11} }{6} = \frac{84}{11} \\ z = \frac{ \frac{504}{11} }{9} = \frac{56}{11} [/tex]
b)x+y+z=42
k/3+k/6+k/9=42 |•18
6k+3k+2k=756
11k=756
k=756/11
[tex]x = \frac{ \frac{756}{11} }{3} = \frac{252}{11} \\ y = \frac{ \frac{756}{11} }{6} = \frac{126}{11} \\ z = \frac{ \frac{756}{11} }{9} = \frac{84}{11} [/tex]
c)x+y+z=84
k/3+k/6+k/9=84 |•18
6k+3k+2k= 1512
11k=1512
k= 1512/11
[tex]x = \frac{ \frac{1512}{11} }{3} = \frac{504}{11} \\ y = \frac{ \frac{1512}{11} }{6} = \frac{252}{11} \\ z = \frac{ \frac{1512}{11} }{9} = \frac{168}{11} [/tex]
* /= linie de fractie
• = ori , semnul inmultirii ×
Sper ca te-am ajutat :)
