college study math test(entrance) need help please

silasraven said:

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)

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RyanTheRhino said:

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

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cannabineer said:

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

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RyanTheRhino said:

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

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cannabineer said:

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


cn

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RyanTheRhino said:

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

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