Question

Quais sao os numeros que somados vale 21 cuja diferencia e igual 5/2

Answer 1

x+y = 21
x-y = 5/2

2x = 21/1 + 5/2
4x/2= 42/2 + 5/2

4x = 42 + 5
4x = 47
x = 47/4
x = 11,75

11,75 + y = 21
y = 21 - 11,75
y = 9,25