Question

Factor x2 – 3x – 28. Identify the values that should be written to complete the X diagram. On the top: On the bottom: On the sides: Rewrite the expression using the numbers on the sides of the X diagram. Use double grouping to factor the four terms. x2 – 3x – 28 =

Answer 1

-28

-3

-7 and 4

(x-7)(x+4)

Answer 2

x^2 -3x -28
= x^2 -7x +4x -28
= x(x -7) +4(x -7)
= (x +4)(x -7)