This is a problem of proportions , were we know what a relationship between two quantities is, and want to find the relationship that is equivalent to it.
So we start saying that $24.80 is to 5 kilos, the same as some unknown price (let's call it "x") is to 8 kilos.
In math terms this is written as:
24.80 : 5 the same as (=) x : 8
which can also be written using fractions:
[tex]\frac{24.80}{5}=\frac{x}{8}[/tex]Notice that in the above expression, we can solve for the unknown "x" (that means isolate x on one side of the equal sign) by multiplying both sides of the equation by the factor "8" thus cancelling the denominator on the right and leaving x on its own on that side of the equal sign:
[tex]x=\frac{24.80\cdot8}{5}=39.68[/tex]So we see that the price we are looking for is $39.68 (for the 8 kilos of the cheese)
