2x+3y=60 solve for x...
x=(60-3y)/2
p=xy^3, using x from above:
p=y^3(60-3y)/2
p=(60y^3-3y^4)/2
dp/dy=(180y^2-12y^3)/2
dp/dy=90y^2-6y^2
dp/dy=0 when:
90y^2-6y^3=0
6y^2(15-y)=0, we know y>0 so
y=15, since x=(60-3y)/2
x=7.5
(We solved it this way because otherwise you get quartic equations and cubic derivatives, yuck :P)
Step-by-step explanation:
a) f(3)=3^2 - 3/2
=9-3/2
=15/2
<em>15.05 ÷ 7 = $2.15 per gallon</em>
<em>--</em>
<em>2.15 x 4 = $8.60</em>
<em>--</em>
<em>jamal can buy 4 gallons of gas</em>
<em />
3.5 think of it as 3.0
C. ——
2.0

Distribute 5 using the Distributive Property:
5(x+24)
Multiply 5 by x:
5x
Multiply 5 by 24:
120
Now, add the products:
5x+120 (Answer)
Hope it helps! Enjoy your day :)
~Just a determined teen
