Question

5x+18=15 3x+9y=12 sistema

Answer 1

5x+18y=15
3x+9y=12 ÷ 3

5x +18y = 15
x+3y=4

x=4-3y

5*(4-3y)+18y=15
20-15y+18y=15
3y=15-20
3y=-5
y=-5/3

x=4-3y
x=4-3*(-5/3)
x=2+15/3
MMC de 1 e 3 = 3
x=6/3 +15/3
x=21/3
x=7