Question #5f8be
3 Answers
Explanation:
I remember receiving this problem before . . . Here's how my math teacher explained it:
You can't factor this the way you normally would with quadratic equations, becuase there are no two numbers whose sum is 7 and whose product is 4.
So, you just have to experiment with the problem by inputting factors of
The answer is:
If you FOIL the expression, you'll end up with the original equation.
Explanation:
In short, bring over the 4 and factor by grouping
You always have to make the equation equal to zero when factoring so in this case you would bring the 4 over.
NOTE: you can get rid of the zero, it doesn't matter now
Then factor by grouping,
- Multiply the last number by the leading coefficient, in this case 15.
15 * -4 = -60
- Don't replace the - 4 with -60 just find two numbers that add up to -7, but multiplies to -60
- In this case it would be -12 and 5
- Now replace the -
#7x# with -#12# and#5#
NOTE: I placed them the way they are so that when we factor it, it will give us whole numbers
- Then factor by splitting the equation in half
- Factor
#15x^2# #+# #5x# and#-12x# #-# 4 individually - Add brackets to separate them
Now since the numbers are the same you can write it as one, then combine what's outside of the bracket together
(
NOTE: You know you did right if the numbers in the brackets are the same
NORMALLY, you would be done, however the
Therefore,
Explanation:
To avoid doing the lengthy factoring by grouping, you may use the new Transforming Method (Socratic, Google Search)
Converted equation:
Proceeding: Find 2 real roots of y', then, divide them by a = 15
The 2 real roots of y' are: - 5 and 12 -->
[Sum = 7 = - b] and Product {ac = - 60]
The 2 real roots of y are:
