MaxWong

Extend it like this:$\begin{bmatrix} 1 && 2 &&-2 &&1&&2\\ 3 && 0 && -1&&3&&0\\ 5 && 3 && 2&&5&&3 \end{bmatrix}$

Multiply the numbers if they can be linked top-to-bottom diagonally with 3 numbers: 

Example: 1, 0, and 2 is in the same diagonal and they are 3 numbers.

Then add up the products obtained from multiplying the number of top-left to bottom-right. Call that 'answer 1'

(1)(0)(2) + (2)(-1)(5) + (-2)(3)(3) = 0 - 10 - 18 = -28 -----(1)

Then add up the products obtained from multiplying the number of top-right to bottom-left. Call that 'answer 2'

(-2)(0)(5) + (1)(-1)(3) + (2)(3)(2) = -10 - 3 + 12 = -1 -----(2)

Add up answer 1 and answer 2: -28 - 1 = -29.

Therefore det(C) = -29. Best method ever , I don't have a proof of it though but I got through the determinant questions correctly when I use this method.

So my answer is 64ft/second, is that correct?

I got 96ft/second for Part 1. Is that correct? because I never did word equation....... 

Why all of them sounded so funny I laughed in front of my computer LOL.

Btw, use the tag [off-topic] when the question is not about Maths, or you can you [Physics] when the question is about Physics.

Title example:  [Off-topic] Spanish

I think you mean : $\dfrac{y^2}{y^7}$

And that equals $y^{2-7} = y^{-5}$OR $\dfrac{1}{y^5}$

43/50 = 86/100 = 86 x 1/100 = 86 x 0.01 = 0.86

Look here..... Exact same question......

I saw you answering when I just started to answer...... And I use LaTeX too. Just practice more and you will be as fast as I am :)

a, b, c means the coefficient of x², x¹, and x⁰ respectively.

Example: In $x^2 - x + 1$ , a = 1, b = -1, c = 1.

In $7x^2 - 22x + 15$, a = 7, b = -22, c = 15.

$\boxed{ \dfrac{a}{b}-\dfrac{x}{y} = \dfrac{ay - bx}{by}}$

$\dfrac{5}{14}-\dfrac{2}{221}\\ =\dfrac{5 \times 221-14\times 2}{14\times 221}\\ =\dfrac{1105 - 28}{3094}\\ =\dfrac{1077}{3094}\\ $

It's the simplest form already, no need to simplify.