Step-by-step explanation:
they're is a neat little trick.
but first of all, "roots" means the 0 solutions of the equation. like
ax² + bx + c = 0
there are 2 solutions for x to make the whole expression equal 0.
these are the "roots".
now to the little trick :
when is a multiplication resulting in 0 ?
when at least one of the factors is 0.
and any quadratic expression can be written as multiplication of 2 factors. like
c(x - a)(x - b) = cx² - cax - cbx + cab
what are the "roots" or 0 points ?
either
c = 0
x - a = 0 | x = a
x - b = 0 | x = b
the leading coefficient = 3.
that means nothing else than c = 3.
root = 1 means (x - 1) is one factor.
root = -5 means (x + 5) is the other factor.
so, we have
3(x - 1)(x + 5) = 3x² + 12x - 15
and the equation is
3x² + 12x - 15 = 0
or
3x² + 12x = 15
Using an linear function, we find that by 2020 only 11% of all American adults believe that most qualified students get to attend college.
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A decaying linear function has the following format:
In which
- A(0) is the initial amount.
- m is the slope, that is, the yearly decay.
- In 2000, 45% believed, thus,
- Decaying by 1.7 each year, thus
.
The equation is:
It will be 11% in t years after 2000, considering t for which A(t) = 11, that is:
2000 + 20 = 2020
By 2020 only 11% of all American adults believe that most qualified students get to attend college.
A similar problem is given at brainly.com/question/24282972
9.50 + (2.20)r
For example if he fixed 3 watches
9.50 + (2.20)3
We plug in 3 for r and he makes 6.60 extra.
Answer:
mean
Step-by-step explanation:
