Question

determina numerele rationale x,y,z ,stiind ca sunt direct proportionare cu 2,3 si 4 ,iar 2x+3y-z=27

Answer 1

2x+3y-z=27
x + 3y + -1z = 27
2x + 3y + -3y + -1z = 27 + -3y
2x + 0 + -1z = 27 + -3y
2x + -1z = 27 + -3y
2x + -1z + z = 27 + -3y + z
2x + 0 = 27 + -3y + z
2x = 27 + -3y + z
x = 13.5 + -1.5y + 0.5z 

Answer 2

{ x,y,z } DP { 2,3,4} = [tex] \frac{x}{2} = \frac{x}{3} = \frac{x}{4} = k - rezulta ca x= 2k , y=3k, z= 4k [/tex]
2x + 3y-z= 27 
2 X 2k + 3 x 3k - 4k = 27
4k + 9k -4k = 27
9k = 27 ( imparti la 9 )
k= 3
x= 2 x 3 = 6
y= 3 x 3 = 9
z= 3x 4 = 12
verficare o faci singur