Si 8 litros de agua contiene 250 gramos de cal ¿que cantidad de agua le debemos agregar para que en cada lito exista 20 gramos de cal?

step-by-step explanation:

i think it's ф or x=6,-6

step-by-step explanation:

-x^2=-36

x^2=-36

ф

or

if you mean by : -(x^2)=-36

it'll be: x^2=36

x=6,x=-6

hope it'll ! have a good day!

you for asking!