college study math test(entrance) need help please

[RyanTheRhino]

[video=youtube;ldYGiXSHa_Q]http://www.youtube.com/watch?feature=player_detailpage&v=ldYGiXSHa_Q[/video]

 

[silasraven]

funniest shit in the world, i get it. BUT i had to google and relearn how to change a dec to a fraction and fraction to a dec and not just once i learned it over after learning it the first time and after learning it the second time today i had to keep google up just to go back and refer to it again because i had to relearn that shit 5-8 times and that was just 2 minutes apart from the problems chances are i'll forget it and relearn it again.

 

[RyanTheRhino]

so this is basic pre-algebra for starters. how many yard of material from a 24 yard length of cloth remain after 3 pieces, each 3 and a half yards long, and 5 pieces, each 2 and a fourth long are removed. heres what i did. 3.5x3=10.5, 2.25x5=11.25 add them 21.75. 24- 21 3/4(.75) is 3 an 3/4 not one of the answers i know is w and 1/4 but how? unless i did some thing wrong

now for the algebra: basic op of polynomials... what is the expression for the product of 3 less than twice x and 2 more than the quantity 3 times x

so i got 6x2(second power)+5x+6 probly wrong but i dont get it. still want to try on that note
product is times so is quantity. i just want to understand it.

sub values into alg expression... 2x(to 3rd power) - 3 xy x=-1 y=2

so its 2(-1)to the 3rd - 3(-1)(2) now where to start... neg times a neg is a pos right?

now for the shit i dont get but want to

for i= -1(to the power before the one) if 3i(2+5i)= x +6i, then x=?

^^^^^ fucken what. dont give me the answers just explain that one. as for the other i remember some of how to do it i just need help finding out how to get the correct answer so when i see this stuff again i know how to do it.

NEVER DROP OUT AND GO TO TUTORING YOUNG FOLKS(im 23 btw)

Ok so your first problem you are on the right track. Learn that 1/2 or "half" is = 0.5, and 1/4 or "fourth" = 0.25 . ( so you have 3 pieces that are 3.5 in length) & ( 5 pieces that are 2.25 in length)
Your total length is 24. So (3x3.5)+(5x2.25) = 10.5 +11.25 = 21.75. Take your total length ans subtract the cuts (24 - 21.75) = 2.25


Problem 2) 3 less = -3, twice x = 2x, two more = +2, 3 times x = 3 x, so (2x-3) & (3x+2)

Problem 3) 2x^3 -3xy =? , x=-1,y=2. ok so in this type of problem you just plug in the values given into the equation.

so since x=-1, y=2, 2x^3 -3xy = 2(-1^3)-3(-1)(2) = 2(-1)+6 = 4. So what happens was -1^3 is just (-1)x(-1)x(-1) multiplying by a negitive 1 just changes the sign .
you start with (-1)X(-1) = 1, now (1) X (-1) = -1 again. this is also why -(3)(-1)(2) = +(3)(2)

problem 4)
i=-1
3i(2+5i) = x+6i.<<<<<< is that i imaginary or just a variable?.. Ill assume this is just a variable at this point. This is the same as the last problem simply plug in -1 where ever you see i

(3)(-1)(2+5(-1) = x +(6)(-1)
-3(2-5) = x -6
-6+15 = x - 6<<< distribute the -3
-6+6 +15 = x
15=x

 

[cannabineer]

Ok so your first problem you are on the right track. Learn that 1/2 or "half" is = 0.5, and 1/4 or "fourth" = 0.25 . ( so you have 3 pieces that are 3.5 in length) & ( 5 pieces that are 2.25 in length)
Your total length is 24. So (3x3.5)+(5x2.25) = 10.5 +11.25 = 21.75. Take your total length ans subtract the cuts (24 - 21.75) = 2.25


Problem 2) 3 less = -3, twice x = 2x, two more = +2, 3 times x = 3 x, so (2x-3) & (3x+2)

Problem 3) 2x^3 -3xy =? , x=-1,y=2. ok so in this type of problem you just plug in the values given into the equation.

so since x=-1, y=2, 2x^3 -3xy = 2(-1^3)-3(-1)(2) = 2(-1)+6 = 4. So what happens was -1^3 is just (-1)x(-1)x(-1) multiplying by a negitive 1 just changes the sign .
you start with (-1)X(-1) = 1, now (1) X (-1) = -1 again. this is also why -(3)(-1)(2) = +(3)(2)

problem 4)
i=-1
3i(2+5i) = x+6i.<<<<<< is that i imaginary or just a variable?.. Ill assume this is just a variable at this point. This is the same as the last problem simply plug in -1 where ever you see i

(3)(-1)(2+5(-1) = x +(6)(-1)
-3(2-5) = x -6
-6+15 = x - 6<<< distribute the -3
-6+6 +15 = x
15=x

I took a similar tack, but got negative customer reviews. cn

 

[RyanTheRhino]

I took a similar tack, but got negative customer reviews. cn

well it helps not to throw an nth power in to a person who is trying to learn what x is.

 

[cannabineer]

well it helps not to throw an nth power in to a person who is trying to learn what x is.

An nth power? Wait, what? cn

 

[RyanTheRhino]

when you where describing why negative numbers to the nth odd power will stay negative

Third one: minus one to the nth power is -1 for all odd n and +1 for all even n, incl. zero.


cn

 

[cannabineer]

when you where describing why negative numbers to the nth odd power will stay negative

I considered that to be both correct and relevant. As the OP is doing polynomial algebra, it's part of the prerequisite toolset, like having memorized times tables and basic exponential values. cn

 

[RyanTheRhino]

well i think of nth terms in this format