Chapter 4 : Algebra

[admin]

Be the first to discuss this chapter!

[jfu.green]

Can someone please explain to me how was one able to come to the conclusion that B is the correct answer?

Also, how did they get 12y and 109?

Thanks!

[sr_vineeth_ruveneco]

Hi jfu.green,

Here is a step-by-step process in solving the equation:

y = 3x^2 - 5x - 7 Step 1: multiply both sides by 12
12y = 36x^2 - 60x - 84 Step 2: add 109 to both sides so that the term on the right can be factored
12y + 109 = 36x^2 -60x +25 Step 3: Factor the right side
12y + 109 = (6x - 5)^2 Step 4: square root both sides
sqrt (12y + 109) = 6x - 5 Step 5: add 5 to both sides
5 + sqrt (12y + 109) = 6x Step 6: divide both sides by 6
5 + sqrt (12y + 109) / 6 = x

Hope this helps!