Question

2x plus 3y plus 40 egal cu 13 7 x plus 5 y plus 30 egal cu 18 Aflati tripliul sumei celor 3 numere​

Answer 1

Răspuns:

2x+3y+40=13

2x+3y=-27

2x=-27-3b

x=-27/2-3b/2

7(-27/2-3b/2)+5y+30=18

-189/2-21y/2+5y+30=18

-189/2-11y/2+30=18

-129/2-11y/2=18

-11y/2=165/2

y=-15

x=-3/2×-15-27/2

x=(45-27)/2

x=9

3(x+y)=3×(9-15)=3×-6=-18