Answer:
[tex]\left \{ {{x = -15} \atop {y=3}} \right.[/tex]
Step-by-step explanation:
[tex]\left \{ {{x + 5y = 0} (1) \atop {3y + 2x = -21}(2)} \right. <=> \left \{ {{x = -5y} \atop {3y + 2x = -21}} \right. <=> \left \{ {{x = -5y} \atop {3y + 2*(-5y) = -21}} \right. <=> \left \{ {{x = -5y} \atop {3y - 10y = -21}} \right. \\<=> \left \{ {{x = -5y } \atop {-7y = -21}} \right. <=> \left \{ {{x = -5y} \atop {y= 3 }} \right. <=> \left \{ {{x = -5 * 3} \atop {y=3}} \right.=> \left \{ {{x=-15} \atop {y=3}} \right.[/tex]
