recognise this equation has the form ax^2 + bx + c =0. An equation with this form is a quadratic. Recognise in a quadratic equation there will be 2 values of x that will equal 0. These 2 values will multiply to make 'ac' add add to make 'b'. In this example, 'ac' is 1x-50=-50, and b is -5. What 2 numbers multiply to make -50, and add up to make -5? -10 and +5 multiply to make -50, and add to make -5. Therefore you would re-write the initial equation as (x-10)=0 and (x+5)=0. These become 2 new equations, now solve for these.x=10 and x=-5. The positive value of x is 10.