math question help, graphing calc needed?

Question

iduno how to use a graphing calc nd dunt have one ><

Use a graphing calculator to tell which of these equations has No solution and which has a solution of All Real Numbers:

a) 1/2x - 5 = 2x -20 over 4

b) 3/2x - 2 = 3 [ x/2 - x ]

also....

this is not graphing
but i dunt get how to do it ><
solve plzz 2/3x - 5 = 1/4 ( x - 5 )

Answer 1

so now their not teaching you math but wanting you to rely on calculators? get your parents to press for that teacher to be fired.

a) your notation is not clear, i will assume you mean
(1/2)x - 5 = (2x-20)/4
just simplify this, but before we do I note there is only one variable (x), so you might expect it to simplify to x = "some constant" which is just a vertical line
but when we multiply both sides by 4, we get
2x-20 = 2x-20
which tells us: x=x (or 0=0)
all real numbers satisfy this: how would a graphing calculator help?

b) I assume you mean
(3/2)x -2 = 3(x/2-x)
3x/2 - 2 = 3(-x/2) = -3x/2
6x/2 - 2 = 0
3x = 2
x = 2/3
this is a vertical line at x=2/3
or if you're confined to only one dimension, then this is just the point x=2/3 on a number line. again, why do you need a graphing calculator for this?


for your 3rd problem
I assume your notation means:
(2/3)x - 5 = (x-5)/4
step one I would get rid of the fractions: multiply both sides by 4 and also by 3 (or multiply by 12 since 3*4=12 to accomplish both at same time)
8x-60=3(x-5)
8x-60 = 3x-15
now subtract 3x from both sides, then add 60 to both sides
8x-3x=60-15
5x=45
divide by 5
x = 9

Answer 2

You definitely don't need a graphing calculator.
First for a. If you simplify 2x-20 over 4, you get 1/2x-5. So a is all real numbers since they are the same line.
For b. Once you distribute the 3 (x/2-x), you get 3x/2-3x. Personally, I do not like fractions, so I multiply the whole equation by 2 (the common denominator) So you would then get 3x-4=3x-6x. Collect like terms and you get 3x-4=-3x. Add 3x to both sides, add 4 to both sides (opposite to get terms on the correct side) and you get 6x=4, meaning x=2/3. Once you substitute the 2/3 in for all the x's in the original problem, you get -1=-1, meaning all real numbers.
For the last non-graphing one, distribute the 1/4 and you will get 2/3x-5=1/4x-5/4. Multiply the equation by the common denominator of 12 and you will get 8x-60=3x-15. Collect like terms and you get 5x=45, with x=9. Substitute the 9 in for all the x's and you will get 1=1.

Hope I could help!!!

Answer 3

a. its all real numbers
b. no solution

you start out with 2/3x - 5 = 1/4 (x-5)
get rid of the parenthesis
2/3x - 5 = 1/4x - 5/4
find common denominators
8/12x -20/4 = 3/12 - 5/4
move the x's on 1 side, and the other numbers on the other
5/12x = 25/4
simplify if possible, i dont know if you can though

Either this ^ is the answer or im completely wrong...you might want a second scource to back it up...

Answer 4

Hello,

For the non graphing problem.

Multiply everything by 12 the commom demoninator. Giving us.

12[2/3x -5 = 1/4(x-5)] or 8x -60 = 3(x-5) so we have

8x -60 = 3x -15 subtract 3x from both sides giving us 5x - 60 = -15 now add 60 to both sides giving us 5x = 45 divide both sides by 3 and we have x = 9.

Hope This Helps!!

Answer 5

i think a is all real numbers and b nas no solution

2/3x-5=1/4x-1.25
2-5=1/4x-1.25(3x)
-3=-3.5x
i think x=.8571..not sure though

Answer 6

a) cant be cuz 2.8x=0
that means x must be zero x=0
should be the second one