Question

the sum of two numbers is 80.if the larger number exceeds four times the smaller number by 5.what is the smaller number

Answer 1

Step-by-step explanation:

let larger number be x and smaller be y

thus, x+y=80, x=80-y

and x-4y=5

on substitution,

80-y-4y=5

80-5y=5

75=5y

y=15

Answer 2

let the two numbers be X and y respectively.

then, X + y = 80

and, x= 4y/ 5

therefore X + y = y + 4y / 5 = 80

$y + \frac{4y}{5} = 80 \\ = > \frac{5y + 4y}{5} = 80 \\ = > 9y = 80 \times 5 \\ = > y = \frac{400}{9}$

it is proved that y is = 400/9

then x = 80 - 400/9 = 320/9