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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