Math, asked by prakriti72, 1 year ago

help me with 25th sum...​

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Answered by Anonymous
8

\mathfrak{\huge{The\:Question\:Says:}}

Divide 20 into two parts such that three times the square of one part exceeds the other part by 10.

\mathfrak{\huge{Answer:}}

Let the parts be = x and y

We know that these numbers are parts of 20. Thus, we can also say that:

\bf{x + y = 20} .....(1)

Now, the given condition is that \bf{3\: times \: the \:square} of one part exceeds the other part \bf{by\:10}

=》 \bf{3x^{2} = y +10}

=》 \bf{3x^{2} - 10 = y} ....(2)

Put (2) in (1) :

=》 \bf{x + y = 20}

=》 \bf{x + 3x^{2} - 10 = 20}

=》 \bf{3x^{2} + x - 30 = 0}

Solve this formed equation further by the splitting middle term method:

=》 \bf{3x^{2} - 9x + 10x - 30}

=》 \bf{3x(x - 3) + 10(x -3)}

=》 \bf{(3x+10)(x-3)}

=》 \bf{x = \frac{(-10)}{3} , 3}\\

Since the first value isn't acceptable, the only value of x can be 3

Therefore , \tt{x = 3}

=》 x + y = 20

=》 \tt{y = 17}

Thus, the numbers will be \huge{\sf{3\:and\:17}}


prakriti72: thanks a bunch
Anonymous: Welcome! :)
Answered by Anonymous
3

Solution :

Assuming the parts as P and Q.

➨ P + Q = 20 ...........(i)

According to the Question ,

➨ 3p² = q + 10

➨ 3p² - 10 = q ............(ii)

Now , putting (ii) in (i) :-

➨ p + q = 20

➨ p + 3p² - 10 = 20

➨ 3p² + p - 30 = 0

Now ,

Let's Solve the equation -

➨ 3p² - 9p + 10p - 30

➨ 3p ( p - 3 ) + 10 ( p - 3 )

➨ ( 3p + 10 ) ( p - 3 )

p = (-10)/3 and 3

Here , appropriate value of p can only be 3.

So , P = 3

➨ p + q = 20

➨ y = 20 - p i.e. 20 - 3

y = 17

Hence ,

The numbers are 3 and 17.


Anonymous: ^^" (˘⌣˘)♪
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