Question

3x+9 = 2y+10
5x+5= 4y+4

Answer 1

Răspuns:

3x+9 = 2y+10

5x+5= 4y+4

----------------------

-2x + 4 = -2y + 10

=> -2x = -2y +6

=> x = y - 3

=> 3x+9 = 2y+10

=> 3(y - 3) + 9 = 2y +10

=> 3y - 9 + 9 = 2y + 10

=> 3y = 2y + 10

=> y = 10

=> x = y - 3

=> x = 7

Verificare :

3x+9 = 2y+10

=> 21 + 9 = 20 + 10

=> 30 = 30 "Adevărat"