Răspuns:
13. 2a+3a=85 5a=85 a= 85:5= 17 a= 17
14. a-29=52 a= 52+29 a= 81
15. a) x*y= 18 2*9=18, 3*6, 9*2 , 6*3
x= 2 y=9 x=3 y=6 x=9 y=2 x=6 y=3
b) (x+3) (y-2) = 18 (x+3)(y-2)= 6*3
x+3= 6 x= 6-3= 3 x= 3
y-2=3 y= 3+2=5 y=5
16. 8a+8b+x=93 8*(a+b)+ x= 93
x= 93- 8*11= 93 -88= 5 x= 5
