Let the positive number be [tex]x[/tex]
The expression is
[tex]x(14+7x)=105[/tex]⇒ expanding the bracket gives,
[tex]14x+7 x^{2} =105[/tex] ⇒ rearranging to equate one side to zero
[tex] 7x^{2} +14x-105=0[/tex] ⇒ Dividing each term by 7 to simplify
[tex] x^{2} +2x-15[/tex] ⇒ Factorising gives
[tex](x+5)(x-3)=0[/tex]
[tex]x=-5[/tex] and [tex]x=3[/tex]
Hence, the first number is -5 and the second number is 3
