1)If (x-2) is a factor of x2+ 3ax -2a, then find the value of a
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Answer:
The percent change in Nancy height is 10%
Step-by-step explanation:
Given : when Nancy started middle school, she was 60 inches tall. when she started high school, she was 66 inches tall.
We have to find the percent change in her height.
Percentage change is given by the ratio of the difference in old value and new value to the old value times 100
Mathematically written as
For the given data,
Old value = 60 inches
New value = 66 inches
Thus, the Percentage change is given as,
Simlify, we have,
Thus, The percent change in her height is 10%
Roots with imaginary parts always occur in conjugate pairs. Three of the four roots are known and they are all real, which means the fourth root must also be real.
Because we know 3 and -1 (multiplicity 2) are both roots, the last root is such that we can write
There are a few ways we can go about finding , but the easiest way would be to consider only the constant term in the expansion of the right hand side. We don't have to actually compute the expansion, because we know by properties of multiplication that the constant term will be
.
Meanwhile, on the left hand side, we see the constant term is supposed to be 9, which means we have
so the missing root is 3.
Other things we could have tried that spring to mind:
- three rounds of division, dividing the quartic polynomial by , then by
twice, and noting that the remainder upon each division should be 0
- rational root theorem