Question 1001108
x, number of cups of flour for cake1.
cake2 uses {{{x+1/2}}} cups flour.
cake3 uses {{{2x}}} cups of flour.


The number of cups of flour is  {{{x+(x+1/2)+2x}}}, and this number of cups is the {{{8&1/2}}} cups of flour bought in the two-pound (puns?) bag of flour.



{{{x+(x+1/2)+2x=8&1/2}}}


{{{4x+1/2=8&1/2}}}


{{{8x+1=17}}}


{{{8x=16}}}


{{{highlight(x=2)}}}, the number of cups flour used for the cake1.