Factor the expression x 2 13x 42 Simplify your answer as mu

Factor the expression x ² +13x + 42. Simplify your answer as much as possible

Factor the expression x ² + 11x. Simplify your answer as much as possible.

Find all real zeros of the function f(x)= x² - 16. Zeros are x=_____

Solution

x^2 + 13x +42

Factorise: x^2 +7x +6x +42

= x ( x+7) +6( x +7)

=(x +6)(x+7)

x^2 +11x

Factorise : x( x+11) ----- taking x as common

f(x) = x^2 -16

Using the formula :(a^2 -b^2) = (a+b)(a-b)

x^2 -16 = (x +4)(x-4)

x^2 -16 =0

(x+4)(x-4) =0

x= -4 , 4 ( zeros of function)