Whats the factoring of a^2-6a-21=-5 ?

So before we can factor this equation, we first have to set the equation to zero. To do this, add 5 on both sides of the equation:

Next, I am going to be factoring by grouping. Firstly, what two terms have a product of -16a² and a sum of -6a? That would be -8a and 2a. Replace -6a with 2a - 8a:

Next, a² + 2a and -8a - 16 separately. Make sure that they have the same quantity on the inside of the parentheses:

Now you can rewrite this equation as , which is your final answer.

the polynomial is a perfect square trinomial of the form a^2-2ab+b^2:

option a. true

step-by-step explanation:

9x^2-12x+4

comparing with the form a^2-2ab+b^2

1.) a^2=9x^2

solving for a: square root both sides of the equation:

sqrt(a^2)=sqrt(9x^2)

a=sqrt(9) sqrt(x^2)

a=3x

2.) b^2=4

solving for b: square root both sides of the equation:

sqrt(b^2)=sqrt(4)

b=2

to be a perfet square trinomial 2ab must be equal to 12x. let's check:

2ab = 2 (3x) (2)

2ab = 12x

correct

step-by-step explanation: