Question

4+n(5-n)÷2+n(7-n)=1 plz solve this i m in 8 th class

Answer 1

Here's your answer:
4+n(5-n) = 2+n(7-n)
4+5n-n^2 = 2+7n-n^2
2n=2
n=1

I hope, I have answered your question.

Answer 2

Let us solve this question step by step for a more clear understanding.

So, the question given is:
$\frac{4+n(5-n)}{2+n(7-n)}$ = 1

Let us cross multiply. We get
4 + n(5-n) = [  2 + n(7-n)  ] x 1
4 + n(5-n) = 2 + n(7-n)

Now, let us multiply n with each term inside the bracket to simplify the equation. We get:
4 + 5n - $n^{2}$ = 2 + 7n  - $n^{2}$ 

Now, let us shift all terms containing n to one side and the constants to another side. (Do remember that when a term is shifted from one side to another, its sign changes).

Thus, we get: 
4 - 2 = 7n - $n^{2}$ + $n^{2}$ - 5n

Since we have + $n^{2}$ and - $n^{2}$ , we can cancel them.
Then, the equation further simplifies to
4 - 2 = 7n - 5n
2 = 2n
n = $\frac{2}{2}$
n = 1

Therefore, n=1 is the required solution.