Answer:
x=7.5
y=1.5
Step-by-step explanation:
[tex]x + y = 9.0[/tex]
subtract x from both sides
[tex]y=9-x[/tex]
[tex]0.50x + 0.20y= 4.05[/tex]
[tex]0.50 x +0.20(9-x)= 4.05[/tex]
[tex]0.50x+1.8-0.2x= 4.05[/tex]
combine like terms
[tex]0.30x+1.8= 4.05[/tex]
subtract 1.8 from both sides
[tex]0.30x=2.25[/tex]
divide both sides by 0.3
x=7.5
[tex]y=9-x[/tex]
[tex]y=9-7.5[/tex]
y=1.5