Question

21,22 cum le fac?ca eu nu le inteleg.

Answer 1

21.
x=y+60
x=y*2+13
y+60=2Y+13
y=60-13=47
47+60=x=107
22.
a=b+31
b+9=a:2
2*b+18-b=31
b+18=31 deci b=13
13+31=44=a

Answer 2

21) x-y=60
x=2y+13
x-y=y+13=60 ⇒ y=47 , x=107
22)x-y=31
y=x/2-9 /*2
2y=x-18⇒x-2y=18 ]
x-y=31                  ]           ⇒y=13 , x=44 
Sper ca ti-am fost de ajutor!  ;)