Based on the fact that Ram bought some pens and they cost Rs.90 but if he had paid Rs.1 less for each he would have 3 more pens, the number of pens he bought is 6 pens.
This can be represented as:
(x + 3) (y - 3) = 90
Where xy = 90
xy - 3x + 3y - 9 = xy
3y - 3x - 9 = 0
y - x - 3 = 0
x - y + 3 = 0
Solving further gives:
x - 90/ x + 3 = 0
x² + 3x - 90 = 0
Remembering that:
90 = 9 x 10
= 3 x 3 x 2 x 5
= 15 x -6
Going back to the formula:
x (x + 15) - 6 (x + 15)
(x + 15) (x - 6) = 0
x - 6 = 0
x = 6 pens
In conclusion, the number of pens bought was 6 pens.
Find out more on solving for missing quantities at https://brainly.com/question/2390480
#SPJ1
