Question

the number of seats in a row is equal to the total number of rows in a hall .the total number of seats in the hall will increase by 375. If the number of rows is doubled and the number of seats in each row is reduced by 5 find the number of rows in the hall

Answer 1

Step-by-step explanation:

no. of seats increased by 375,rows reduced =5,rows are equal to seats.let the number of rows in a hall. 375+x=1, x=1- 374,374 -5=369 rows

Answer 2

The number of rows in the hall is 25.

Step-by-step explanation:

The number of seats in a row is equal to the total number of rows in a hall .

Let x be the number of rows in the hall.

Total seats = $x\times x=x^2$

If the number of rows is doubled and the number of seats in each row is reduced by 5, then the total number of seats in the hall will increase by 375.

Total seats after adjustment is

$2x\times (x-5)=x^2+375$

$2x^2-10x=x^2+375$

$2x^2-10x-x^2-375=0$

$x^2-10x-375=0$

Splitting the middle term we get

$x^2-25x+15x-375=0$

$x(x-25)+15(x-25)=0$

$(x+15)(x-25)=0$

$x=-15,25$

Number of rows can not be negative.

Therefore, the number of rows in the hall is 25.

#Learn more

15 X square + 3 x minus 18 factoriz e using middle term splitting technique.

https://brainly.in/question/6671544