Question 398627
let a pepperoni pizza be {{{x}}} and a ham pizza be {{{y}}}


{{{(1/2)x + (3/4)y = 765cal.}}}....(1)

{{{(1/4)x + y = 745cal.}}}.......(2)
-----------------------------------------solve this system



{{{(1/2)x + (3/4)y = 765cal.}}}....(1)solve for {{{x}}}


{{{4(1/2)x + 4(3/4)y = 4*765cal.}}}

{{{cross(4)2(1/cross(4))x + cross(4)(3/cross(4))y = 3060cal.}}}


{{{2x + 3y = 3060cal.}}}


{{{2x =3060cal-3y}}}.....divide by {{{2}}}


{{{x  = 1530cal-(3y/2)}}}.....plug it in (2) and solve for {{{y}}}



{{{(1/4)x + y = 745cal.}}}.......(2)


{{{(1/4)(1530cal -(3/2)y) + y = 4*745cal.}}}..........multiply by 4


{{{4(1530cal/4) - 4(1/4)(3/2)y + 4y = 4*745cal.}}}

{{{1530cal - (3/2)y + 4y = 2980cal.}}}

{{{1530cal - 1.5y + 4y = 2980cal.}}}

{{{1530cal +(3.5)y = 2980cal.}}}



{{{ (3.5)y = 2980cal-1530cal}}}


{{{ (3.5)y = 1450cal}}}


{{{ y = 1450cal/(3.5)}}}


{{{ y = 414.3cal}}}


now find {{{x}}}



{{{x  = 1530cal - 3y/2}}}.

{{{x  = 1530cal - 3(414.3cal)/2}}}.

{{{x  = 1530cal - 621.45cal}}}.

{{{x  = 908.55cal}}}.


check:

{{{(1/2)x + (3/4)y = 765cal.}}}....(1)

{{{(1/2)908.55cal + (0.75)414.3cal = 765cal}}}

{{{454.275cal + 310.725cal = 765cal}}}

{{{765cal  = 765cal}}}