Question

Aflati metoda figuranta (grafica) numerele ,,x'' si ,,y'' stiind ca relatiile din fiecare grupa(perche) sunt verificate simultan : b) x-y=40 x=5 ori y d) x+y=27 x:y= 5 rest 3 e) x-y=18 x:y=3 g) x+y=20 x=4 ori y

Answer 1

b) x-y=40
x = 5*y ( * = inmultit)
inlocuiesti pe x in ecuatie
5y-y=40 => 4y=40 => y = 40:4 => y=10
d) x+y =27
x:y = 5 rest 3 => x = 5*y+3
x+y=27=> 5*y+3+y=27 => 6y+3 = 27 =? 6y = 27-3=> 6y = 24 => y = 24:6 => y=4
e)x-y=18
x:y=3 => x = 3*y
x-y=18 => 3*y - y =18 => 2y =18 => y =18 : 2 => y=9
g)x+y=20
x=4*y
x+y=20=> 4*y+y=20=> 5y=20 => y = 20 :5 => y =4