CPhill

3.42   = 3 + 42/100  = 3 + 21/50  =  171 / 50

0.004  = 4 / 1000  =  1 / 250

We don't know......this isn't an equation......it's just an expression.....x could equal anything

8x = x - 16      subtract x from both sides

7x  = -16       divide both sides by 7

x = -16 / 7

V = (1/3) Bh    multiply each side by 3

3V  = Bh         divide each side by h

3V / h   = B

-13 < 4 x + 3    subtract 3 from both sides

-16 < 4 x          divide both sides by 4

-4 < x      or,  expressed differently..........x >  -4

(8 / 9)  / (2 / 15)       invert the second fraction and multiply

( 8 / 9 ) * (15 / 2)  =

(8 / 2) * (15 / 9)  =

4 * ( 5 / 3)  =

20 / 3   =  6 + 2/3

This function doesn't ever appear to equal 0.....see the graph, here.........https://www.desmos.com/calculator/gbffzpgnyt

It appears that the graph has a horizontal asymptote at y = 4 and the function never crosses this.

I believe that you're trying to use "Heron's Formula" to find the area of a riangle when you only know the three sides.

The formula  is:

A = sqrt [ s (s - a) (s - b) (s - c) ]           where "s"  is the semi-perimeter and a, b and c  are the triangle sides

And  s =  [  a + b + c] / 2     [add the three sides and divide by 2]

Here's an example......suppose  a triangle has sides of 6, 8 , and 10.....find the area

s = [ 6 + 8 + 10 ] / 2   =   24 / 2 = 12

A = sqrt[ 12 (12- 10) (12 - 8) (12 - 6) ]

A = sqrt [ 12 * 2 * 4 * 6]

A = sqrt [ 24 * 24]   = 24 sq units

And that's it    !!!!

 l 12 l   means the "absolute value" of 12........the distance 12 is from 0 on the number line.......this  = 12

So

- l 12 l   =  - the absolute value of 12 =    - 12