Josie deposited $450 in bank account. At begin of month. $35.20 is automatically deducted each month. At end of 4 months how muc
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Answer:
x=2 or x=8
Step-by-step explanation:
I find it easiest to factor the equation, but you might find it easier to use the quadratic formula. Both will be shown.
<u>Factoring</u>
It is helpful to understand the relationship between the trinomial and its binomial factors:
(x +a)(x +b) = x^2 +(a+b)x +ab
This tells you the constant (ab = 16) will have two factors (a, b) that have a sum equal to the x-coefficient (a+b = -10).
We can list the factorization of 16 to see which factor pairs match that requirement:
16 = -1×-16 = -2×-8 = -4×-4
The sums of these factors are, respectively, -17, -10, -8. The pair with a sum of -10 is the one of interest. This tells us the equation factors as ...
(x -2)(x -8) = 0
The zero product rule tells us that for the product to be zero, one or more of the factors must be zero. The first factor will be zero when x=2; the second factor will be zero for x=8.
The zeros of the quadratic are x=2 or 8.
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<u>Quadratic Formula</u>
The general form of a quadratic equation is often written as ...
And the general solution of this quadratic is given by the formula ...
Your equation has a=1, b=-10, c=16, so the quadratic formula gives the zeros as ...
As before, the zeros are 5-3 = 2, and 5+3 = 8.