Question

7)rezolvati prin metoda substitutiesi sistemeele:
a)6(x-y) + 3y+5=2x
8(x-2y)+4=3x-10y

b)5(4x-3y)+16y-3=24x
5(x-3y)-9x=3-16y

Answer 1

a)  6x-6y+3y=2x=>6x-2x-6y+3y=0=>4x+3y=0
     8x-16y+4=3x-10y=>8x-3x-16y+10y=-4=>5x+6y=-4
4x+3y=0
5x+6y=-4
b)20x-15y+16y-3=24x=>20x-24x-15y+16y=3=>-4x-y=3
5x-15y-9x=3-16y=>5x-9x-15y+16y=3=>-4x-y=3
-4x-y=3
-4x-y=3   
-y=4x+3
-4x-4x-3=3
-8x=3+3
x=-6/8
nu stiu mai mult de atat