The equation for this is ax^2+bx+ c. You get the answer by finding factors of A and C; multiply them to each other so example after you find a factors of A which would be D and E, and B which would be F and G; multiply D with F and E with G. After that see if the two answers you got add or subtract to get the same number as B. Find both of the factors like for this example the best factors to use for A well is 1•1 because thats the only factor possible and for C the best factor is 3•7 because since there both just multiply by one if you add them together you get 10. After you do all that this is the formula (Dx+/-G)(Ex+/-F) plug all the numbers in and then you get the answer (1x+7)(1x+3) more formal way:(x+7)(x+3)
P.S if you want to check its right make it back into a quadratic equation: (D•E)(D•F)+(G•E)+(G•F)=ax^2+bx+c