Answer:
(a) 3 - 2x - 2x² (b) -21
Step-by-step explanation:
given, y +2x² = 3 -2x
make y the subject:
y = 3 - 2x - 2x²
if y = f(x)
then
f(x) = 3 - 2x - 2x²
(b)<u> to find f(3) we need to replace x with 3:</u>
<u />
3 - 2(3) - 2*(3)²
-21
<h2>
Explanation:</h2>
The nth term of an arithmetic series (
) and the sum of an arithmetic series (Sum), for n terms, can be found as:
![a_{n}=a_{1}+d(n-1) \\ \\ Sum=\frac{n}{2}[2a_{1}+(n-1)d] \\ \\ \\ Where: \\ \\ a_{1}:First \ term \\ \\ d:Common \ difference \\ \\ n=Number \ of \ term](https://tex.z-dn.net/?f=a_%7Bn%7D%3Da_%7B1%7D%2Bd%28n-1%29%20%5C%5C%20%5C%5C%20Sum%3D%5Cfrac%7Bn%7D%7B2%7D%5B2a_%7B1%7D%2B%28n-1%29d%5D%20%5C%5C%20%5C%5C%20%5C%5C%20Where%3A%20%5C%5C%20%5C%5C%20a_%7B1%7D%3AFirst%20%5C%20term%20%5C%5C%20%5C%5C%20d%3ACommon%20%5C%20difference%20%5C%5C%20%5C%5C%20n%3DNumber%20%5C%20of%20%5C%20term)
So, in this exercise:
![a_{1}=a=9 \\ \\ d=4 \\ \\ n=16 \\ \\ \\ Sum=\frac{16}{2}[2(9)+(16-1)4] \\ \\ Sum=8[18+(15)4] \\ \\ Sum=8[18+60] \\ \\ Sum=8[78] \\ \\ \boxed{Sum=624}](https://tex.z-dn.net/?f=a_%7B1%7D%3Da%3D9%20%5C%5C%20%5C%5C%20d%3D4%20%5C%5C%20%5C%5C%20n%3D16%20%5C%5C%20%5C%5C%20%5C%5C%20Sum%3D%5Cfrac%7B16%7D%7B2%7D%5B2%289%29%2B%2816-1%294%5D%20%5C%5C%20%5C%5C%20Sum%3D8%5B18%2B%2815%294%5D%20%20%5C%5C%20%5C%5C%20Sum%3D8%5B18%2B60%5D%20%5C%5C%20%5C%5C%20Sum%3D8%5B78%5D%20%5C%5C%20%5C%5C%20%5Cboxed%7BSum%3D624%7D)
<h2>Learn more:</h2>
Missing numbers in triomino: brainly.com/question/10510270
#LearnWithBrainly
Answer:
-5.6k-7
Step-by-step explanation:
you'd start by multiplying 6 by everything in the first pair of parentheses:
6(-2.1k-2)= (-12.6k-12)
then you'd add the like terms together:
(-12.6k-12)+(7k+5)= -5.6k-7
