if you isolate y in the top equation to get y=5x+6 then you can substiture y for 5x+6 in the bottom equation because thats what y equals
as of now you have -3x+6(5x+6)=-12 but if you use the distrubite property you would get -3x+30x+36=-12
then if you subtract 36 from both sides you would get -3x+30x=-48 then combine like terms to get 27x=-48 then divide both sides by 27 to get
or x≈1.8
All you have to do is take the size for every cereal, divide it with its price and you should get your answer as cents. then compare them all and see which one has the lowest price.
* don't forgot to put place holders and add a decimal.
(72/80)x90=81
Divide seventy-two by eight and multiply it Ninety.