Question

Aflati numerele rationale pozitive x si y stiind ca:

x/3=y/8 si x+t =22

x/y=4/9 si 2x+3y=40

5x=3y si 4y - 3x =0,11

Answer 1

x/3=y/8 si x+y =22
y=8x/3
x+8x/3=22
3x+8x=66
11x=66
x=6
y=8×6/3=16

x/y=4/9 si 2x+3y=40
y=9x/4
2x+3×9x/4=40
2x+27x/4=40
8x+27x=160
35x=160
x=160/35=32/7
y=9/4×32/7=72/7

5x=3y si 4y - 3x =0,11
y=5x/3
4×5x/3-3x=0,11
20x/3-3x=11/100
2000x-900=33
1100x=33
x=0,03=3/100
y=5×0,03/3=0,15/3=0,05=1/20