Question

regrinha de Cramer 2x-3y=7 5x+y=8​

Answer 1

Resposta:

$S=\{(\frac{31}{17},-\frac{19}{17})\}$

Explicação passo a passo:

Resolva o sistema pela regra de Cramer:

$\left \{ {{2x-3y=7} \atop {5x+y=8}} \right. \\\\D=\left|\begin{array}{ccc}2&-3\\5&1\\\end{array}\right| \\\\D=2.1-5(-3)\\\\D=2+15\\\\D=17\\\\D_x=\left|\begin{array}{ccc}7&-3\\8&1\\\end{array}\right| \\\\D=7.1-8(-3)\\\\D=7+24\\\\D_x=31\\\\x=\frac{D_x}{D} \\\\x=\frac{31}{17} \\\\d_y=\left[\begin{array}{ccc}2&7\\5&8\\\end{array}\right] \\\\D_y=2.8-5.7\\\\D_y=16-35\\\\D_y=-19\\\\y=\frac{d_y}{D}\\\\y=-\frac{19}{17}$