The sum of two numbers is 9 and their differecne is 3

let's use x to represent the unknown number

and let y=3

solution

x+y=9

x+3=9

x=9-3

x=6

therefore 6 is the unknown number

so

6+3=9

Step-by-step explanation:

Let the numbers be x and y. Now, We have to follow the question's statement. First of all, we have to form equations according to the question's statement.

Solve the question by elimination method.

Put the value of y in equation 1.

Therefore, the required values are 6 and 3.

36 girls

step-by-step explanation:

the 48 boys is 4 parts of the ratio

divide 48 by 4 to obtain one part of the ratio

= 12 ← 1 part of the ratio

3 parts = 3 × 12 = 36 ← number of girls