Help walk me though these please? I fan and medal!
How many real# solutions does these equations have?
a. -7x²+6x+3=0

b. -8x²-8x-2=0

Question

Help walk me though these please? I fan and medal! 
How many real# solutions does these equations have?
a. -7x²+6x+3=0

b. -8x²-8x-2=0

jack1 · Answer

a: 2
b:1

jack1 · Answer

should we start with a?

jack1 · Answer

are you familiar with the equation:
-b   +/-  ( sqrt (b^2 - 4ac) ) / 2a

anonymous · Answer

i might be but the way 2 typed it doesnt ring any bells (sorry)

anonymous · Answer

jack1 is right, u substitute you a, b, c values in this equation

jack1 · Answer

a quadratic equation takes the form of:
$$y = ax ^{2} + bx + c$$

jack1 · Answer

the x - intercepts occur when the equation of the line crosses the x-axis, which is a y=0

jack1 · Answer

as it's a curve (all quadratic equations are), this may not happen at all or may happen up to twice

jack1 · Answer

so from the quadratic equation, a, b, and c are all numbers, while y and x are variables

jack1 · Answer

a. -7x²+6x+3=0
so from your first equation: a is -7;   b is 6;   and c is 3

anonymous · Answer

ok

jack1 · Answer

so shoot a quick look at this page, and take special notice of the equation near the top: http://www.purplemath.com/modules/quadform.htm

anonymous · Answer

Thanks!!!

jack1 · Answer

all good
so your x intercepts for eqn 1 are:
0.35388 and -0.35388 ...ish

jack1 · Answer

whereas for equation 2, it only just touches the x axis, and really forms a tangent with it at its turning point (point of highest inflection) at x = -1/2

anonymous · Answer

ok, thanks again. i finally get it!!