McGraw Hill Integrated II, 2012
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McGraw Hill Integrated II, 2012 View details
6. Solving x^2+bx+c=0
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Exercise 40 Page 50

Practice makes perfect
a

We need to use the Distributive Property to complete the table.

Product of Two Binomials ax^2+mx+px+c ax^2+bx+c m* p a* c
(2x+3)(x+4) 2x^2+8x+3x+12 2x^2+11x+12 24 24
(x+1)(3x+5) 3x^2+5x+3x+5 3x^2+8x+5 15 15
(2x-1)(4x+1) 8x^2+2x-4x-1 8x^2-2x-1 - 8 - 8
(3x+5)(4x-2) 12x^2-6x+20x-10 12x^2+14x-10 - 120 - 120
b

From the table in Part A, we see that the product of m and p is equal to the product of a and c.

m * p = a * c
c

The second and third column in the table shows us that the sum of m and p is equal to b.

m + p = b
d

To factor trinomials in the form ax^2+bx+c, we first need to find two numbers, m and p, with a product of a* c and a sum of b.

ax^2+bx+c ⇕ ax^2+mx+px+c This expression can be factored by grouping.