Can you explain how to do these math questions?

Question

Simplify the expression
3x-12/x^2-4x

and
Multiply, simplify if possible
5x+5/3 multiplied by 6/20x+20

They have no paranthesis

Answer 1

Can you verify that these are fractions that need parentheses?

For 3x-12/x^2-4x, do you mean:
(3x-12)/(x^2-4x)

And for 5x+5/3 multiplied by 6/20x+20, do you mean:
(5x+5)/3 multiplied by 6/(20x+20)

If you mean those, then you need to factor the numerator and denominator so that:
(3x-12)/(x^2-4x)
= [3(x-4)]/[x(x-4)]
= 3/x (cancel out the x-4)


And for (5x+5)/3 multiplied by 6/(20x+20), you may save some time by factoring first, so you get:
{[5(x+1)]/3} * {6/[20(x+1)]} =
(5/3) * (6/20) (cancel out the x+1)
= 1/2

Edit: While the original problem may not have had parentheses, it may be required when writing them online. It requires some sort of equation editor to create an object where you can easily have a numerator and a denominator.

To give an example, "2x^2-4/2x+3" is very different from "(2x^2-4)/(2x+3)".

Answer 2

well i assume its (3x-12) / (x^2 - 4x)
factorise 3x - 12 => 3 (x-4)
" x^2 - 4x => x (x-4)
u see x-4 in both nominator and denominator. therefore wad's left is 3/x.

similarly i assume (5x+5)/3 X 6/(20x+20)
5(x+1) X 6
3 20(x+1)
Do some cancellation
5 x 2
20
= 1/2

Answer 3

sorry - last person was wrong...
3x-12/x^2-4x....simplifies to 3(x-4)/x(x-4)...which after cancelling like terms is equal to 3/x

Answer 4

well, im pretty sure the second one is:
1.5x^2 + 100.5x + 33 & 1/3
(the 33 and 1/3 is one number also 33.3 {with last three repeating})

Answer 5

the first one:

3(x-4)/x(x-4) = 3 / x

the second one:

1/2

Answer 6

3x-12/x^2-4x
combine like terms: 3x - 4x = -1x giving
-x - 12/x^2