The number of boys and girls in a class are in the ratio 5:4. If the number of boys is 9 more than the number of girls, then number of
boys is 9

no.of boys is 45

Step-by-step explanation:

here, let the number of boys and girls be 5x and4x

ATQ,

5x=4x+9

or,5x-4x=9

or,x=9

then, the number of boys is 9×5=45

and the number of girls is 9×4=36..

3< x< 5

step-by-step explanation:

|x - 4| < 1

there are two solutions, one positive and one negative.   remember to flip the inequality when taking the negative solution

x-4 < 1       x-4 > -1

add 4 to each side

x-4+4 < 1+4       x-4+4 > -1+4

x< 5                 x> 3

3< x< 5