\left \{ {{5x+6y=10} \atop {2x-3y=4}} \right.⇒ \left \{ {{5x+6y=10} \atop {2(2x-3y)=2*4}} \right. ⇒ \left \{ {{5x+6y=10} \atop {4x-6y=8}} \right. ⇒ \left \{ {{9x=18} \atop {2x-3y=4}} \right. ⇒ \left \{ {{x=18:2=9} \atop {2*2-3y=4}} \right. ⇒ \left \{ {{x=2} \atop {4-3y=4}} \right. ⇒ \left \{ {{x=2} \atop {4-4=3y}} \right. ⇒ \left \{ {{x=2} \atop {0=3y}} \right. ⇒ \left \{ {{x=2} \atop {y=0:3=0}} \right.