Question

reposted plz answer the questions

Answer 1

Question 1 B.


1 . 4m² - 25n²

= > ( 2 )²m² - ( 5 )²n²

= > ( 2 m )² - ( 5 n )²


From the properties of factorization, we know : -
a² - b² = ( a + b )( a - b )


Therefore,

= > ( 2 m )² - ( 5 n )²

= > ( 2 m + 5 n )( 2 m - 5 n )


Hence, factorized.



2 .

In the question, it is given that the ratio of two numbers in 3 : 5 and if 10 is added to both the numbers, ratio becomes 19 : 25

Let the required numbers are 3 a and 5 a,


According to the question : -

= > ( 3 a + 10 ) : ( 5a + 10 ) = 19 : 25

= > 25( 3 a + 10 ) = 19( 5 a + 10 )

= > 75a + 250 = 95a + 190

= > 250 - 190 = 95a - 75a

= > 60 = 20a

= > 3 = a


Therefore,
Required numbers are :

• 3 a = 3( 3 ) = 9
• 5 a = 3( 5 ) = 15

$\:$

Answer 2

1. (2m)²- (5n)² = (2m+5n) (2m-5n)

2. 3x + 10/5x + 10 = 19 / 25
= 75x 5x + 250 = 95x + 190 (by cross multiplaction)
= -20x = - 60
= x = 3