Answer:
![\[\sqrt{5}\]](https://tex.z-dn.net/?f=%5C%5B%5Csqrt%7B5%7D%5C%5D)
Step-by-step explanation:
The given vector is represented by (2,-1).
This can be represented in general form as (x,y) where x=2 and y=-1.
Magnitude of the vector represented as (x,y) is given by ![[\sqrt{x^{2}+y^{2}}\]](https://tex.z-dn.net/?f=%5B%5Csqrt%7Bx%5E%7B2%7D%2By%5E%7B2%7D%7D%5C%5D)
Evaluating for the given values of x and y,
![\[\sqrt{2^{2}+(-1)^{2}}\]](https://tex.z-dn.net/?f=%5C%5B%5Csqrt%7B2%5E%7B2%7D%2B%28-1%29%5E%7B2%7D%7D%5C%5D)
![\[=\sqrt{4+1}\]](https://tex.z-dn.net/?f=%5C%5B%3D%5Csqrt%7B4%2B1%7D%5C%5D)
![\[=\sqrt{5}\]](https://tex.z-dn.net/?f=%5C%5B%3D%5Csqrt%7B5%7D%5C%5D)
Length of the vector is
Hello,
Please, see the detailed answer in the attached files.
Thanks.
Answer:
C. -7x^2 - 28
Step-by-step explanation:
Firstly simplify the bracket before doing anything;
4x(3x - 7) = 12x^2 - 28x
then go back to the question and substitute the expression(12x^2 - 28x) on the bracket and then work out the question;
12x^2 - 28x -19x^2...then group the values with the same exponent of x,
(12x^2 - 19x^2) - 28x
; -7x^2 - 28x
