Question

Need help and a memory refresher on 8 problems.. Please do not give me answers. I want to remember how to solve them. This is my midterm review.

Answer 1

11. Perform the indicated operations and write in standard form.

(-10 + square root -9) ^2

Answer 2

16. Solve the problem.

A rain gutter is made from sheets of aluminum that are 24 inches wide. The edges are turned up to form right angles. Determine the depth of the gutter that will allow a cross-sectional area of 58 square inches. There are two solutions to this problem. Round to the nearest tenth of an inch.

Answer 3

21. Solve the linear inequality. Other than not solution sign, use interval notation to express the solution set and graph the solution set on a number line.

x-1 over 16 >/ x-4 over 20 + 1 over 80

Answer 4

@jim_thompson5910 @welshfella @Nnesha

Answer 5

Please help me finish. I still have a chapter test and midterm to do for another class. Im majorly behind since the system keeps glitching.

Answer 6

@IrishBoy123

Answer 7

Hopefully in your lesson somewhere you learned that \[\Large i = \sqrt{-1}\] ? or no?

Answer 8

Yes I did last term.

Answer 9

ok great

Answer 10

what we can do is rewrite -9 as -1*9 and simplify like this

\[\Large \sqrt{-9} = \sqrt{-1*9}\]
\[\Large \sqrt{-9} = \sqrt{-1}*\sqrt{9}\]
\[\Large \sqrt{-9} = i*3\]
\[\Large \sqrt{-9} = 3i\]

make sense?

Answer 11

Yes!

Answer 12

\[\Large \left(-10+\sqrt{-9}\right)^2\]
turns into
\[\Large \left(-10+3i\right)^2\]

Answer 13

Yep I have that.

Answer 14

Next you'll use the box method or FOIL or the distributive property to expand out
\[\Large \left(-10+3i\right)^2\]

Answer 15

personally I like the box method but you can choose which one you want to do

Answer 16

So..
(-10+3i)(-10+3i)

Answer 17

yes

Answer 18

keep going

Answer 19

I got..
100-51i

Answer 20

incorrect

Answer 21

Yeah...

Answer 22

Not sure where im going wrong..

(-10+3i)(-10+3i)
100-30i-30i+9i
100-60i+9i
100-51i

Answer 23

3i times 3i = 9i^2

not just 9i

Answer 24

since i = sqrt(-1), squaring both sides gives i^2 = -1

Answer 25

Omg -.-

Answer 26

91-60i

Answer 27

perfect

Answer 28

Okay. For number
16. Solve the problem.

A rain gutter is made from sheets of aluminum that are 24 inches wide. The edges are turned up to form right angles. Determine the depth of the gutter that will allow a cross-sectional area of 58 square inches. There are two solutions to this problem. Round to the nearest tenth of an inch.

I got to
-20+- square root 296 all over -4

Answer 29

the square root 296 can turn into 2 square root 74

Answer 30

-20 +- 2 square root 74 all over -4

Then I can -20 and -4 --> 5

Answer 31

I'm kinda stuck there.

Answer 32

I'm not sure how you got that. What quadratic equation did you get to?

Answer 33

Um..
-2x^2 +20x -13=0

-20+- square root (20)^2 -4(-2)(-13) all over 2(-2)


Some girl earlier said to-
2x+y=20
y=20-2x
x*y=13

x*(20-2x)=13

Answer 34

Im really not sure. I followed what she said. And I responded saying I was stuck and she didnt reply.

Answer 35

ok let's start with a 24 inch line

Answer 36

we will bend this line into a partial rectangle like this



I can't do animations on here but hopefully you can picture what is going on

Answer 37

I can.

Answer 38

after the bending is done, we have this left over

Answer 39

if we make x = depth, then we have this