Question 166079
I'm sure your teacher is not crazy.:)
Anyway, I'll try and help;
First of all we know he spends $312 all together. Now lets break that down. To make small milkshakes it cost .45 for each, and for large it cost .75 for each.
So the equation would be;
x = small milkshakes
y = large milkshakes
.45x + .75y = 312
Now the lther equation;
We know he wants to make $1410 altogether, he charges 2.25 for small and 3.00 for large.
So the equation;
2.25x + 3y = 1410
Now we have our two equations, lets solve them.
.45x+.75y = 312
2.25x+3y = 1410
========================
let solve the first for y;
.75y = 1410-.45x
{{{y = (1410)/.75 - (.45x)/.75}}}
y= 416-.6x
Now plug this into either equation for y to find x;
2.25x +3(416-.6x)=1410
2.25x + 1248 - 1.8x=1410
.45x+1248=1410
.45x=162
x=360
Now we have our x, lets find out y;
.45(360)+.75y=312
162 + .75y = 312
.75y = 150
{{{y = 150/.75}}}
y=200
Check
.45(360) + .75(200)=312
Hope you understand
:)