Polynomials with degree 2 are called quadratic polynomials. When this
polynomial is equated to zero, we get a quadratic equation.
Its general form is a2 + bx + c = 0, where a, b and c are real numbers and a 'I- 0.
In many real life situations, we deal with quadratic equations.
Suppose, we have to make a table of 50m2 area with its length twice as its
breadth then,
o: 0 zx A
Let x be the breadth of the table Therefore, its length will be 2x
Since, length x breadth = area
Therefore, x.2x = 50
So, 2x2 = 50 (quadratic equation)
x2 =25 that gives, x = 5
Thus the length of that table will be = 2x = 1 Om and breadth will be 5m.
EXERCISE - 4.1
Represent the following statements mathematically:
Q.1 Rahul and Nikhil together have 50 chocolates. Both of them lost 5
chocolates each and the product of number of chocolates they have now is
300.Find how many chocolates they actually had?
Sol.
Let, x be the number of chocolates Rahul had Then, the total number of
chocolates Nikhil had = (50 - x) chocolates.
After loosing 5 chocolates Rahul had (x - 5) chocolates and Nikhil had (50 - x -
5) chocolates.
Now, according to the given condition:
(x - 5) (45 - x) = 300
45x - x2 - 225 + 5x=300
NCERT SOLUTIONS CLASS 10 MATHS
CHAPTER 4 - QUADRATIC EQUATIONS
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