We have two numbers say a, b. And a system of equations.
[tex]a+b=0\wedge\dfrac{a+b}{15}+10(a+b)=1[/tex]
It looks a bit intimidating but it's actually very easy.
Instead of term a + b in the second equation we can say it's zero because the first equation describes a + b as being equal to 0.
So,
[tex]\dfrac{0}{15}+10\cdot0=1\Longrightarrow 0+0=1[/tex]
The above equation is not true therefore numbers a and b do not exists in the real number domain.
[tex]a,b\notin\mathbb{R}[/tex]
No solution.
Hope this helps.