Question

aflati trei nr naturale stiind ca doua cate doua au media aritmetica egala cu 17,23 respectiv 25

Answer 1

(x+y):2=17

(y+z):2=23

(x+z):2=25

⇒x,y,z=?

x+y=17·2

x+y=34

y+z=23·2

y+z=46

x+z=25·2

x+z=50

⇒x+y=34

y+z=46

x+z=50

x+y+y+z+x+z=34+46+50=130

2x+2y+2z=130

(x+y+z)+(x+y+z)=130

x+y+z=130:2=65

x+y+y+z=34+46=80

(x+y+y+z)-(x+y+z)=y

80-65=15

y=15

x+y=34

x=34-15

x=19

x+z=50

z=50-19

z=31

⇒x=19

y=15

z=31