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Maths Exercices
Applications of quadratic equations


Suppose a rectangle has an area of 90m2 and the sides are x+1 and x+2. Find the dimensions of the rectangle.
(x+1)·(x+2)=90
x2+3x+2=90
x2+3x-88=0
(x+11)·(x-8)=0
x+11=0; x=-11
x-8=0; x=8
The sides are 9m and 10m long.

A person spent 240 euros to buy several objects. If each object had been  8 cheaper he or she could have bought 5more. How many object does he or she buy? What is the price of each object?

He or she buys objects at euros each.