Question

Help me find the y determinant!

Answer 1

Choose the value of the y determinant (Dy) in the following system.
2x - y = 7
3x + 4y = 5

Answer 2

Do you know how to find the determinate period?

Answer 3

Swap out the y coefficients with the answer column

Answer 4

So just find the determinate of this matrix:\[
\begin{bmatrix}
2 & 7 \\
3 & 5
\end{bmatrix}
\]

Answer 5

how?

Answer 6

\(\left[
\begin{matrix}
2&-1&| &\color{red}{ 7}\\
3& 4& | & \color{red}{5}
\end{matrix}
\right]\implies
D_y = \left[
\begin{matrix}
2&\color{red}{7}\\
3& \color{red}{5}
\end{matrix}
\right]
\)

Answer 7

You must know how to find a determinant by now...

Answer 8

oh ok..so what is the final answer?

Answer 9

I forgot how to sorry

Answer 10

agree on that with @wio

Answer 11

well, if you forgot, it's about time to open up the book and recheck the material

Answer 12

I'm pretty sure it's there

Answer 13

how do I find the answer?

Answer 14

by rereading the chapter on finding the determinants

Answer 15

http://www.math.dartmouth.edu/archive/m8s00/public_html/handouts/matrices3/node7.html

Answer 16

-11

Answer 17

yes

Answer 18

got it..now do I find the x determinant of this one? 4x - y = 5
3x + 2y = 7

Answer 19

can you help me set it up?

Answer 20

\(
\left[
\begin{matrix}
4&-1&| &\color{red}{ 5}\\
3& 2& | & \color{red}{7}
\end{matrix}
\right]\implies
D_x = \left[
\begin{matrix}
\color{red}{\square?}&-1\\
\color{red}{\square?}& 2
\end{matrix}
\right]
\)

Answer 21

5 and 7?

Answer 22

yes

Answer 23

can you help me with one more?

Answer 24

None of the choices seem right to me

Answer 25

which means that
80 = 2 * 2 * 2 * 2 * 5 = \(\bf 2^4 \times 5\)
\(\bf \Large 2\sqrt[4]{80} \implies 2\sqrt[4]{2^4\times5}\)