i think its right... but isnt x multiplied by x is x"2 (it means that the 2 'd b above but i dont have that shift here lol)
soo it 'd be 6x'2 + 12x lol i dunno if its right... i am just in ninth grade lol
you sure there isnt any squares on the first one :?...i thought it might be factorising and exapanding...or it could be simplifying and expanding...yup i think so
the first example only requires simplifying. add/subtract like terms and you are left with the answer.
to simplify the second example you need to first expand the brakets. this means multiplying everything out side with the inside..do this in steps as not to confuse things. so to expand the brakets would be: -3x X -2x and then -3x X -4. the minus(negative number) becomes a positive when multiplied by another minus. then you simplify what your left with in the same way as your first example. erm i hope this is what your askin.
In the first example you have an equation of the first degree in the form of ax+b=0
In such equations the solution is x=-b/a
Now your example isn't in it's root form, if we alter it a bit we'll find -2x+5x-7+8x=0
=> 4x+0=0
So the solution is x=-b/a=-0/4=0
The second equation you have is of teh second degree something in teh form of ax^2+bx+c=0
It's a bit modified so it's tricky to recognise.
-3x(-2x-4)=0
=> 6x^2+12x+0=0
Now there's different ways to solve such an equation. Normally we'd have to calculate teh discriminant first, but since teh "c" value is zero; that makes it a lot easier to solve. In fact I shouldn't have modified it to this forme since it's previous form is easier to work with. I only did this to show you that we're actually dealing with a quadratic equation here.
Now lets' solve it first of all quadratic equations have two solutions. Sometimes the solutions are imagenary numbers that cannot be expressed in simple mathemetics but there will always be to solutions.
So -3x(-2x-4)=0
For the product of two numbers to equal zero eithe one or both of the products need to equal zero.
That means either -3x=0 or -2x-4=0
We now have two equations of teh first degree giving us one solution each.
-3x=0 => x=0
and -2x-4=0 =>x=-2
So in conclusion what is the difrence?
1. The first one is a 1st degree equation, while the second one is a second degree equation, also refered to as quadratic equation.
2. The first one has one solution whereas the second one has two solutions
Hope this helps. If there's further questions don't hesitate
kay: