Help in Algebra?

Question

Please explain to me how to answer these questions. Somehow I don't remember learning how to solve or find the value of x -maybe I wasn't in school when it was being taught or maybe it did't have to be taught because it looks so easy but I don't know how to answer it right. Please help me, thanks so so much.. :-)

1. If x(x – 3) = 0, then
A. x = 0 only
B. x = 3 only
C. x = 0 or x = –3
D. x = 0 or x = 3

2. If x(x – 1) = 2, then
A. x = 1 or x = 2
B. x =–1 or x = –2
C. x = –1 or x = 2
D. x = 1 or x = –2

3. If (x – 2)(x – 3) = 0, then
A. x = 2 or x = 3
B. x = 2 or x = –3
C. x = –2 or x = 3
D. x = –2 or x = –3

Thanks again..

Please find all values of x which satisfy the equation.

Hey! Thanks for all your help. It really helped me a lot.. :0)

Answer 1

1. D

2. x^2- x- 2 = 0>>>>(x-2)(x+1) = 0>>> x = 2, -1>>> C

3. A

Why a Freaking Thumb Down ? Asked a Question, got an answer? Damn man what's the matter with people?!
Is This how you say Thank You??!!

To have a correct record :Next answer was posted 5 minutes After !

Answer 2

For these, you need to substitute the given values for x and see if it works.

In the first one, you're told that x(x-3) = 0. So two numbers multiplied give zero. You know that anything multiplied by zero gives zero, so either x or x-3 must be zero. That means that x can be zero, or x can be 3.

In the second one, x times x-1 is 2. Try the possibilities given: if x=1, then the left hand side of your equation reads: 1(1-1). Since 1-1 is zero, the answer would be 0 rather than 2, so x can't be 1. Now try x=2 as a possibility. The left side of the equation then reads 2(2-1) which is 2x1, which is 2. So x=2 is a valid solution.

Now try similarly with the other values of x.

Answer 3

1. Look a * b = o if and only if a = 0 or b = 0
In your case: x = 0 or x - 3 = 0
Answer D.

2. you have to remove the brackets first:
x(x - 1) = x^2 - x, therefore you have:
x^2 - x = 2 - since it is a quadratic equation, move everything to the one side:
x^2 - x - 2 = 0, factorize:
(x - 2)(x + 1) = 0

follow the above:
x - 2 or x + 1 = 0
C

3. Already factorized. Follow the above:
x - 2 = 0 or x - 3 = 0
A

Good Luck,

Kempos

Answer 4

1. x(x-3)=0 First off, since the two quantities are being multiplied by one another and the equation is equal to 0..you can separate each part and solve it

x=0 and x-3=0
so x=0 and x=3

2. x(x-1)=2 Since the equation does not equal 0, you need to subtract the two to the other side..
x-2(x-1)=0

x-2=0 and x-1=0
x=2 and x=1

3. (x-2)(x-3)=0 The equation is set to equal to 0 and the two quantities are multiplied together, so you can set each part equal to 0.

x-2=0 and x-3=0
x=2 and x=3

Answer 5

What is the value of zero times anything? If all else fails then replace x with all the possible values and solve each one.

Answer 6

1. D
2. A
3. A

Answer 7

sorry don't know