[tex] \left \{ {{x-4y=22} \atop {2x+5y=-21}} \right. \\\\x=22+4y\ \ \ \ \ \ \ \ |substituting\ to\ the\ second\ equation\\2(22+4y)+5y=-21\\44+8y+5y=-21\\8y+5y=-21-44\\13y=-65\\y=-5\\x=22+4(-5)\\x=22-20=2\\\\ \left \{ {{y=-5} \atop {x=2}} \right. [/tex]
