maths
posted by sunny on .
i am trying to solve 4/x2>5. i use calculator and mistakenly type of digit if other than 5. when i type in the problem ,so i get the wrong solution my answer was 2<x<y. what did i mistakenly type in?

4 / x  2 > 5
4 / x > 5 + 2
4 / x > 7 Multiply both sides with x
4 > 7 x Divide both sides with 7
4 / 7 > x
This mean:
x < 4 / 7
x must be > 0 besouse in expresion:
4 / x  2 > 5
4 / 0 = undefined
So solution are:
0 < x < 4 / 7 
For negative numbers 4 / x  2 is always negative so negative numbers canĀ“t be sloutions.