please help me how to solve for x:?

Question

x/2-3=1/7

x(squared)-7x-19=0

0.03724x+0.2214=3.9715

(x-1)(x+1)+(x-1)(x+2)=0

thanks
please really help me answer and don't answer do your own homework, i just don't get these problems!

Answer 1

1)
x/2 - 3 = 1/7
x/2 = 3 1/7
x = 6 2/7

2)
x^2-7x-19=0
using the quadratic equation
x = 3.5 plus or minus 2.5*(5^1/2)

3)
0.03724x + 0.2214 = 3.9715
0.03724x = 3.7501
x = 100.7

4)
(x - 1) (x + 1) + (x-1) (x+2)=0
x^2 - 1 + x^2 + x - 2 = 0
2x^2 + x - 3 = 0
(2x + 3) (x - 1) = 0
then
(2x + 3) = 0 or (x - 1) = 0
2x + 3 = 0
2x= -3
x = -1 1/2
or
x - 1 = 0
x = 1
x is 1 or -1.5

Answer 2

The first one is a basic equation - like most things, it just looks hard; it isn't really. Take it a piece at a time to make sense of it:
x/2 - 3 = 1/7
So you have a number on both sides of the = sign; why not move the 3 over to the other side, so you have the 'x' term on one side and a plain number on the other.
You can do this by adding 3 to both sides (you have to do the same thing to both sides of the equal sign or you change the equation).
OK, x/2 - 3 + 3 = 1/7 + 3
That becomes x/2 = 1/7 + 3
Why don't we turn the '3' into a fraction with a 7 in the denominator so we can combine the two numbers?
x/2 = 1/7 + 21/7
so x/2 = 22/7
Now we're getting somewhere!
Let's get rid of that pesky "/2" under the 'x': we'll multiply both sides of the equation by 2 (remember we have to do the same thing to both sides).
So now we have x/2 * 2 = 22/7 * 2
That becomes x = 44/7, right? Now all you have to do is simplufy the fraction so it shrinks down to 6 2/7.
Is that right? Let's check:
6 2/7 divided by 2 = 3 1/7. Now subtract 3 and *ta-da*, you're left with 1/7.
The third one is just the same, with decimals instead of fractions. You can handle that, right?
The second and fourth look tricky because they involve x squared, but they're not as painful as they look - try banging on them for a while using this technique and see how far you get - I bet you can figure it out.

Answer 3

#2) x(squared)-7x-19=0

Use the quadric function.. The answer to find the roots.. They are 7+(the square root of) 27 / (divided by) 2..
or 7- (the square root of) 27 / 2
(sorry, idk where the square root botton is on the computer)
you have to have both answers for it to be correct.

Answer 4

im postive on these two
3) 0.009930
4) 1