factor xsquared-7x-30 completely

Question

a. (x-1)(x+30)

b. (x-5)(x+6)

c. (x-10)(x+3)

d. (x+2)(x-15)

Answer 1

( X+ a)( X+b) = X² + ( a+b)X+ ab

 

   This is a general formula, where Multiplying binomial by binomial result in a trinomial( polynomial of 2nd degree or quadratic).

     You have to be able to factor any quadratic 2 two binomial, and solve it.

     and expand it.

 

      ( X-1) ( X +30) = X² + 29X - 30

       

       ( X - 5) ( X +6 ) = X² + X -30

 

        ( X + 2) ( X -15) = X² - 13X - 30    You see that Coeficient of X is ( a+b) and constant is ab

     

Answer 2

c. just expand it.