X = Numero de personas
Y = Aporte de cada uno
XY = 1200
Y - X = 194
Y = 1200 / X
(1200 / X) - X = 194
(1200 - X²) / X = 194
1200 - X² = 194X
0 = X² + 194X - 1200 ; donde a = 1 ; b = 194 ; c = - 1200
<img src="https://tex.z-dn.net/?f=X%3D%5Cfrac%7B-b%5Cpm%20%5Csqrt%7Bb%5E2-4ac%7D%7D%7B2a%7D" />
<img src="https://tex.z-dn.net/?f=X%3D%5Cfrac%7B-194%5Cpm%20%5Csqrt%7B194%5E2-4%281%29%28-1200%29%7D%7D%7B2%281%29%7D" />
<img src="https://tex.z-dn.net/?f=X%3D%5Cfrac%7B-194%5Cpm%20%5Csqrt%7B37636%2B4800%7D%7D%7B2%7D" />
<img src="https://tex.z-dn.net/?f=X%3D%5Cfrac%7B-194%5Cpm%20%5Csqrt%7B42436%7D%7D%7B2%7D" />
<img src="https://tex.z-dn.net/?f=X%3D%5Cfrac%7B-194%5Cpm%20%5Csqt%7B206%7D%7D%7B2%7D" />
X1 = [ - 194 + 206] / 2 = 6
X2 = [ - 194 - 206] / 2 = - 200
Uso X1 = 6
Rta : 6 personas.