Question

Three times the larger of two numbers is equal to four times the smaller. The sum of the numbers is 21 . Find the number

Answer 1

two numbers equal 21
x+y=21
x<y
3y=4x
y=4x/3
x+4x/3=21
7/3x=21
7x=63
x=9
9+y=21
y=12

Answer 2

`x,y-\ two\ numbers\ , x-\ smaller\\\\ x+y=21\ \ \ \ | x=21-y\\ 3y=4x\\\\ 3y=4(21-y)\\\\ 3y=84-4y\ \ \ | add\ 4y\\\\ 7y=84\ \ \ \ | divide\ by\ 7\\\\ y=12\\\\ x=21-12=9\\\\ Smaller\ number:\ 9\\\\ Larger \ number:\ 12`