?

can someone show me how (2x-4)^2=3x^3-6x is x=2, x=8?? 

An equilateral triangle has in centimeters the side lengths x + 2y, 5y - x and 3x - y where x and y are positive integers. Determine the smallest possible circumference of the triangle.

I thought ........

x+2y=5y-x=3x-y

2x=3y

x=1.5y

circumference of the triangle: (x+2y)+(5y-x)+(3x-y)

Then I do not know how I can solve thisproblem, I thought that maybe you could solve it with an equation system..... ???

But I dont know how. Can someone show me step by step because I want to learn. I only know that the answer is going to be 21cm. 

Use difference of two squares. Determine the value of without a calculator A^2 - B^2 if 

A=2012^x + 2012^-x

B=2012^x-2012^-x.

I only know that the answer is going to be 4.

Can someone show me how I can get that answer step by step?thank you.

write 20^2-12^2 as a power of 2. Use the difference of two squares.

I know that the answer is going to be 2^8, But the problem is that I dont know how I can solve this, can someone show me step by step?

I only know that 20^2-12^2=(20+12)(20-12) (difference of two squares.) But then I dont know.....how can you solve this without a calculator? 

The positive numbers x and y are solutions to the equations x^4 - y^4=2009 and x^2 + y^2=49.

Determine x and y.

How can you solve this problem with for example: Difference of two squares/ (a+b)^2=a^2+2ab+b^2 or (a-b)^2=a^2-2ab+b^2

The answer is going to be : x=(45)^(1/2) and y=2

Can someone show me how I can get these answers step by step? I need to learn this.

 Thank you.

determine three consecutive integers so that the product of the two largest numbers is 200 more than the product of the two smallest numbers.

The answer is going to be: 99, 100, 101. 

Can someone show me step by step how I can get those answers? Thank you.

For which values of the number a 

 xa + 2a = x + 2a^2 is an identity

The answer is going to be a=1. How can I get that answer? Can someone show me step by step because I want to learn. Thank you.

for which values of the number t the equation is an identity

a) t(x+2)=x+t

b) t(x-1)=x-t

the answers is going to be: 

a) no t

b) t=1

I dont understand can someone show me step by step how I can get get those answers because I want to learn. 

Alex chooses four numbers. a, b, c, and d. For each of the numbers, he determines the sum of the numbers and the mean of the other three. He gets the following sums 60, 64, 68, and 72. Determine the mean of the numbers a, b, c, and d.

I need to solve this problem by using System of equations. How can I solve this? Can someone show me step by step. I really want to learn.

 I know that the answer is going to be 33.

Thank you.

determine all (x, y) that are solutions to the equations.

x^2+y^2 = x-2xy+y and,

x^2-y^2=x+2xy-y

I dont understand this question (what do they even want me to do?), can someone please show me step by step. Because I want to learn. 

I only know that the answers is going to be: (0.0) , (0.1) , (1,0), (1,-1)

Thank you.

x^2 + y^2 =225

x^2 + z^2 =169

y+z=14

can someone show me how I can solve this step by step. Because I dont understand :(

I only know that the answers are going to be : x=12, y=9, z=5 but I want to learn how I can solve this.  Thank you.

if the slope is -3.

what is a.

if the Points are: (1-a, 3) and (3, 2+a)

I need to get the answer a=-5/4

If every eighth person smokes, and nine out of ten who get lung cancer are smokers. How many times higher is the risk of getting lung cancer for a smoker than one who does not smoke.

how do I get the answer 63??? can someone explain?? thank you.

If you throw a roll with two Dice, the probability that the sum will be twelve is equal to 1/36. What is the probability that the sum will not be twelve?

How do I get the answer: 35/36 

can someone show me how I can get that answer. Thank you.

You throw with a six-sided dice.

Calculate the probability that the result is evenly divisible by two or three.

I need to get the answer: 2/3 

Can someone show me how I can get that answer? thank you.

what is a and b if

y=m*(1/x)

x1=4 

x2=12 

x3=b 

y1=a 

y2=18 

y3=72

I need to get the answers: a=54, b=3

how can get those answers can someone help me out, thank you.

what is a and b if

y=m*x^2

x1=4

x2=12

x3=b

y1=a

y2=18

y3=72

I need to get the answers: a=2, b=24. 

how can get those answers can someone help me out, thank you.

In an isosceles triangle, the two equal sides are 3.0 cm. The length of the base b cm depends on the size of the top angle a°. Determine the Domain of the function and the range for the function b(a).

how can the answer be: 

0 < a < 180 , and

0 < b < 6

I don't understand anything…. can anyone explain this… Thank you.

x+(2x/3)+(x/2)+(x/7)=97

how do I solve this equation step by step? can someone show me, I need to get the answer x=42