Answer:
(-3;2)
Step-by-step explanation:
if the first equation is -5x+21=18y, then:
[tex]\left \{ {{y=2x+8} \atop {-5x+21=18*(2x+8)}} \right. \ => \ \left \{ {{y=2x+8} \atop {-5x+21=36x+144}} \right. \ => \ \left \{ {{y=2x+8} \atop {41x=-123}} \right. \ => \ \left \{ {{y=2} \atop {x=-3}} \right.[/tex]
