Question

Resolva o sistema

2x + 5y = 12
3x + 2y = 2

Answer 1

Pelo método da substituição:
$\left \{ {{2x+5y=12 (I)} \atop {3x+2y=2(II)}} \right. \\ (I)2x = 12-5y=\\ x = 6- \frac{5}{2}y \\\\ (II)3*(6- \frac{5}{2}y)+2y=2\\ 18- \frac{15}{2} y+2y=2$

MMC(2,1)=2

$\frac{36-15y+4y}{2}= \frac{4}{2}\\ 36-15y+4y=4\\ 36-9y=4\\ -9y = -32\\ 9y=32\\ y=\frac{32}{9} = 3,555555... \\ x=(6- \frac{5}{2}* \frac{32}{9}) \\x = (6 - \frac{160}{18})\\ x = 6 - 8,9 \\x=-2,9\\ \\ x = -2,9\\y=3,5$