Algebra
posted by Jenny .
i forgot how to solve these types of problems..
2x^218x=0, x^2=6x+7, 6y^2+5y6=0
Also
SOLVE FOR X CORRECT TO 4 DECIMAL PLACES:
x^2+6x+2=0 2x+4=3x^2

For the first bit of the question, get all the terms over onto the lefthand side of the equation. For example, take the second one:
X²6X7=0
Usually you can factorize it easily into the following form: (X+A)(X+B). (There's no guarantee that it's an easy factorization, but if you're expected to solve it this way it usually is.)
If you multiply out those two brackets, you'll get X² + (A+B)X + AB.
So in this example, if you compare the corresponding terms from the two equations, A + B = 6 and AB = 7. So what are A and B? Usually you can spot it in a few seconds...
How about A = 1 and B = 7?
One down, two to go...