Thread: [SOLVED] Quadratic equation problem...URGENT

The cost of an anorak rose by 6 pounds. As a result a shop could buy fewer anoraks for 600 pounds.
If the cost of the anorak was x pounds before the rise, fin expressions, in terms of x, for the number of anoraks which could be bought before and after the rise.
Hence form an equation in x and show how is reduces to x^2 +6x-720=0

Hello, Helena!

There's some information missing.
I'll take a guess at what it is.

The cost of an anorak rose by $6.
As a result, a shop could buy five fewer anoraks for $600.

If the cost of the anorak was dollars before the rise,
find expressions, in terms of , for the number of anoraks
which could be bought before and after the rise.

For $600, at dollars each, we can buy: . anoraks.

For $600, at dollars each, we can buy: . anoraks.

Hence, form an equation in
and show how it reduces to:

. .


Multiply by

. . . . . . . . . . . . . . .

. . . . . . . . . . . . . .


. . . . . . Divide by 5: .

Originally Posted by Soroban

Hello, Helena!

There's some information missing.
I'll take a guess at what it is.

For $600, at dollars each, we can buy: . anoraks.

For $600, at dollars each, we can buy: . anoraks.



. .


Multiply by

. . . . . . . . . . . . . . .

. . . . . . . . . . . . . .


. . . . . . Divide by 5: .

Thanks a lot for your help! I only have one question:
Where do you get the 5 from?
I'm not supposed to solve the equation mentioned until after I have derived the formula...so if you did it the other way around and got the 5 that way...is there an other way of doing it? (I'm not told that they can buy 5 in the question, so...)