Need help in excersise...

HI... I don't understand this excersises... can someone.. do it for me.. and the explain it to me please... thanks!!!!

1 --- Solve: 2x^2 = 14x + 20

and

2 -- Solve: 3x2 + 4x = 2... (this one I need the finnal part of the quadratic equation.. but i don't knoq how to do it).. thanksssss

OK

2x^2 = 14x + 20; your best bet is to get it all on one side and make it equal 0, like this:

2x^2 -14x -20 = 0; Now at this point, I would factor - but it looks like this is NOT factor-able (had the equation originally be 14x -20, you would have had a factor-able solution)

14 +-sqrt(196 - (4)(2)(-20))/ 4
14+-sqrt(196 + 160) / 4
14+-sqrt(356) /4
14+-2sqrt(89) /4
7+-sqrt(89)/2

7+sqrt(89)/2 and 7-sqrt(89)/2
7+9.433/2 and 7-9.433/2
16.433/2 and -2.433/2
8.2165 and -1.2165

Proof:
2(8.2165)^2 = 14(8.2165) + 20 ??
2 (67.51) =115.03 +20?
135.03 = 135.03 YES!!


Second one:
3x^2 + 4x -2 = 0

-4 +-sqrt(16 -(4)(3)(-2) / 6
-4 +-sqrt(16+24) /6
-4+-sqrt(40) /6
-4+-2sqrt(10)/6
-2+-sqrt10 /3

-2+sqrt10 /3 and -2-sqrt10 /3
-2+3.162 /3 and -2-3.162 /3
1.162/3 and -5.162/3
.3873 and -1.721

Proof
3(.3873)^2 + 4(.3873) = 2??
3(.15) + 1.549 = 2??
.45 + 1.55 = 2??
2 =2 YES!!

Hope that helps.

They both require the quadratic equation.

1) 2x^2 = 14x +20
Subtract 14x from each side
2x^2 -14x =20
Subtract 20 from each side
2x^2 -14x -20 = 0 now it's ready for the quadratic equation

2) Same thing:

3x^2 + 4x -2 = 0.

2x^2=14x+20

2x^2-14x-20=0

2(x^2-7x-10)=0
2

a=1 b=-7 c=-10
x=7+/- sq rt -7^2-4(1)(-10)/2

x=7+/- sq rt 49+40/2
x=7+/- sq rt 89/2

x=2(7+/- sq rt 89/ 2)

3x^2+4x-2=0

a=3 b=4 c=-2

x=-4+/- sq rt 4^2-4(3)(-2)/6
x=4+/- sq rt 16+24/6
x=4+/- sqrt 40/6
x=4+/- 2 sq rt 10/6
x=2+/- sq rt 10/ 3