Ask question

Ask question

All categories

4 years ago

15

Help!!!!!!!!! i need this asap!

1 answer:

Nutka1998 [239]4 years ago

4 0

$A=\left[\begin{array}{ccc}3&0\\2&-1\end{array}\right]\\\\B=\left[\begin{array}{ccc}2&8\\0.6&3\end{array}\right]\\\\A\cdot B=\left[\begin{array}{ccc}3&0\\2&-1\end{array}\right]\cdot\left[\begin{array}{ccc}2&8\\0.6&3\end{array}\right]=\left[\begin{array}{ccc}(3)(2)+(0)(0.6)&(3)(8)+(0)(3)\\(2)(2)+(-1)(0.6)&(2)(8)+(-1)(3)\end{array}\right]\\\\=\left[\begin{array}{ccc}6&24\\3.4&13\end{array}\right] \to\boxed{A.}$

You might be interested in

Does anyone knoe how to do this?? help

wlad13 [49]

Answer:

it has to be a fraction and this is really hard try looking at a video about this on go ogle

Step-by-step explanation:

3 0

3 years ago

Read 2 more answers

Help!! 50 points and brainliest!

Viktor [21]

Answer:

Second choice:

$x=2t$

$y=4t^2+4t-3$

Fifth choice:

$x=t+1$

$y=t^2+4t$

Step-by-step explanation:

Let's look at choice 1.

$x=t+1$

$y=t^2+2t$

I'm going to subtract 1 on both sides for the first equation giving me $x-1=t$ . I will replace the $t$ in the second equation with this substitution from equation 1.

$y=(x-1)^2+2(x-1)$

Expand using the distributive property and the identity $(u+v)^2=u^2+2uv+v^2$ :

$y=(x^2-2x+1)+(2x-2)$

$y=x^2+(-2x+2x)+(1-2)$

$y=x^2+0+-1$

$y=x^2$

So this not the desired result.

Let's look at choice 2.

$x=2t$

$y=4t^2+4t-3$

Solve the first equation for $t$ by dividing both sides by 2:

$t=\frac{x}{2}$ .

Let's plug this into equation 2:

$y=4(\frac{x}{2})^2+4(\frac{x}{2})-3$

$y=4(\frac{x^2}{4})+2x-3$

$y=x^2+2x-3$

This is the desired result.

Choice 3:

$x=t-3$

$y=t^2+2t$

Solve the first equation for $t$ by adding 3 on both sides:

$x+3=t$ .

Plug into second equation:

$y=(x+3)^2+2(x+3)$

Expanding using the distributive property and the earlier identity mentioned to expand the binomial square:

$y=(x^2+6x+9)+(2x+6)$

$y=(x^2)+(6x+2x)+(9+6)$

$y=x^2+8x+15$

Not the desired result.

Choice 4:

$x=t^2$

$y=2t-3$

I'm going to solve the bottom equation for $t$ since I don't want to deal with square roots.

Add 3 on both sides:

$y+3=2t$

Divide both sides by 2:

$\frac{y+3}{2}=t$

Plug into equation 1:

$x=(\frac{y+3}{2})^2$

This is not the desired result because the $y$ variable will be squared now instead of the $x$ variable.

Choice 5:

$x=t+1$

$y=t^2+4t$

Solve the first equation for $t$ by subtracting 1 on both sides:

$x-1=t$ .

Plug into equation 2:

$y=(x-1)^2+4(x-1)$

Distribute and use the binomial square identity used earlier:

$y=(x^2-2x+1)+(4x-4)$

$y=(x^2)+(-2x+4x)+(1-4)$

$y=x^2+2x+-3$

$y=x^2+2x-3$ .

This is the desired result.

3 0

4 years ago

Read 2 more answers

Megan ate lunch at a restaurant. The bill came to $99. If she left an 18% tip, what was the total cost of her lunch?

Rashid [163]

$116.82. I hope this helps. Please give brainliest I really need this brainly to make my mom proud lol : === )

7 0

2 years ago

Read 2 more answers

In Ms. Henrick's class, there are 10 boys and 12 girls. What is the ratio of boys to girls? Express your answer as a fraction in

vodomira [7]

Answer:

the ratio is 10:12 and if you were to write it in a fraction you get 10/12 which can be simplified as 5/6

5 0

3 years ago

Read 2 more answers

PLS HELP ME ON THIS QUESTION I WILL MARK YOU AS BRAINLIEST IF YOU KNOW THE ANSWER!!

olga nikolaevna [1]

Answer:

b or d

Step-by-step explanation:

igxgkztjsy,hfzfjzitzgmzfjztzutzjvahfzgkzjrJt

7 0

3 years ago

Read 2 more answers