Math

[reeses4life]

1. Is ( 0, 3) a solution to the equation y = x + 3?

Yes
No

2. Is ( 1, -4) a solution to the equation y = -2x?

Yes
No

3. Look at the following points:

( 4, 0)
( 3, -1)
( 6, 3)
( 2, -4)

Which are solutions to y = x - 4
(2 correct answers)

A. ( 6, 3)
B. ( 4, 0)
C. ( 3, -1)
D. ( 2, -4)


4. Give an example of an open equation




5. How can you use an equation to make a prediction from a pattern?



6. Pizza costs $1.50 per slice. Use a table and an equation to represent the relationship between the number of slices of pizza bought and the total cost.


I think
1. Yes
2. No
3. ( 4, 0) and ( 3, -1)

I need help with 4, 5, and 6.

[reeses4life]

Wait my answer to 4 is: Well, an algebraic open equation (also known as an open sentence) is a mathematical equation that is neither true nor false. so an example of an open equation could be x + 3 = 7 or 2x = 12

and 6: y=1.50x; y=total number of slices x= the amount of slices 1.50=the cost of one slice

[Calibax]

6
y = 1.5x
e.g.
(0,0)
(2,3)
(3,4.5)
(10,15)

[Mexican18]

Gobbledegook!

[reeses4life]

So is everything else right?

[pixie374]

The others are right.

[fiction-factory]

1 yes because 3=0+3

[Zacs-Master]

Twelvety!

[fiction-factory]

2 no because when x=1 y=-2

[Prudie]

The open question one evaded me as I've not heard the term before so I googled and found this entire question and your suggested answers on another site!!
X + 3 =7 seems clear to me and not open at all, I'd have thought more along the lines of x + y = 7 so I clearly don't get the open bit.

[Peter Pedant]

I dont want to do all your prep
yes 1,2, and 3 are right
6
slices number s and cost c
1s costs 1.5
2s costs 3
3s costs 4.5 and we see by inspection c = 1.5s
where c is the cost and s in the number of slices

5 oh describe what you did in 6
construct a table with the pairs of values
inspect and detect a pattern

4 - .........x + 2 = 7 is open because it is true for x=5 but not for anyting else ( ie true sometimes and false sometimes) which means NOT always true and NOT always false
x + X = 2X is a closed sentence as it is always true
at school we used to call closed sentences 'identities'

[New Judge]

Just the one "Math", is it?

[Peter Pedant]

Prudie it is the beginning of mathematical logic
( for all x, x+x=2x ) - is closed because the 'for all x' bit covers all the variables
rather than for all x ..... x+y = z where the for 'all x bit' does NOT cover y and z - hence open - ( actually closed for x and open for y and z but what the hell)

excellent that they are doing this at skool
usually university stuff -
I did gook at it and think - hey this is about quantifiers - bit advanced for skool innit ?
like this
https://en.wikipedia.org/wiki/Universal_quantification

[New Judge]

"...usually university stuff - "

It may be now, Peter, but it wasn't when I was at skool.

[Peter Pedant]

//Just the one "Math", is it?//

just the one - darn sarf it's "maff "of course

same stuff we did but with different vocab
didnt Gauss say - non notatione sed notione
( not by notation but by notion) - notice cute instrumental ablative without 'ab' only used with persons
yes he did

so they get " does the vector/ordered pair (1,2) satisfy y =2x ?"
whereas we got - "does x=1, y=2 satisfy y = 2x"

same ship different colour

[Peter Pedant]

jesus you did quantifiers at skool ?
upside down A and upside down E and all that jazz ?
we didnt ( A levels 1968)

[goodgoalie]

Ah, but you ain't an OO like NJ, Peter!

[New Judge]

Indeed.