So for this, we will create a system of equations. With our information given, these are our two equations (let x = advance and y = same-day):
[tex]x+y=65\\20x+30y=1700[/tex]
So for this system, I will be using the substitution method. With the first equation, subtract both sides by y:
[tex]x=65-y\\20x+30y=1700[/tex]
Now that we know that x is equal to 65 - y, substitute that into the second equation and solve for y:
[tex]20(65-y)+30y=1700\\1300-20y+30y=1700\\1300+10y=1700\\10y=400\\y=40[/tex]
Now that we know the value of y, substitute that into either equation to solve for x:
[tex]x+40=65\\x=25\\\\20x+30(40)=1700\\20x+1200=1700\\20x=500\\x=25[/tex]
In short: