求下列二次方程! (完全不懂) HELP ME......

1.
9(y-1)^2-144=0
(y-1)^2=16
y-1=16 or y-1=-16
y=17or-15

2.
7(x+4)^2+28=0
(x+4)^2=-4
x+4=2i or x+4=-2i
x=-4+2i or x=-4-2i

3.
4y^2-15y+9=0
y=3or0.75

4
56(5x+7)+48x^2=0
280x+392+48x^2=0
x=-0.4or-0.6

5.
x(16x-2)=15/2
16x^2-2x=15/2
32x^2-4x=15
32x^2-4x-15=0
x=0.75or-0.625

6
(3y+19)(y-4)=10
3y^2-12y+19y-76=10
3y^2+7y-86=0
y=4.31or-6.64

7
7(x+4)^2+28=0
(x+4)^2=-4
x+4=2i or x+4=-2i
x=-4+2i or x=-4-2i

8
4(x-5)^2-49=0
(x-5)^2=49/4
x-5=3.5 or x-5=-3.5
x=8.5or-1.5

9
18y^2-25y-3=0
y=1.5or-1/9

10
92x(x+3)=161
92x^2+276x-161=0
x=0.5or-3.5

11
x+21/2=3x^2/2
-3x^2+2x+21=0
x=-7/3or3

12
(y+1)(3y-8)=20
3y^2-8y+3y-8-20=0
y=4or-7/3

13
6y(y+4)=(2y-3)(y+4)
6y=2y-3
4y=-3
y=-3/4

14
2(11z+3)(12z+6)=(7z+8)(12z+6)
22z+6=7z+8
15z=2
z=2/15

15
4(z+5)^2=2(z+5)(3z+2)
4z+20=6z+4
2z=16
z=8

16
(2y+5)^2=(3-4y)^2
2y+5=3-4y
6y=-2
y=-1/3

1) 9(y-1)^2-144=0
(y-1)^2=16
y-1=±4
y=±4+1
=-3 or 5//
2)7(x+4)^2 +28=0
(x+4)^2+4=0
(x+4)^2= -4
x+4=±2i
x=±2i-4
=2i-4 or -2i-4//
3)4y^2 -15y+9=0
(y-3)(4y-3)=0
y=3 or 3/4 //
4) 56(5x+7)+48x^2=0
7(5x+7)+6x^2=0
6x^2+35x+49=0
(3x+7)(2x+7)=0
x=-7/3 or -7/2 //
5) x(16x-2)=15/2
16x^2-2x=15/2
32x^2-4x-15=0
(4x-3)(8x+5)=0
x=3/4 or -5/8 //
6) (3y+19)(y-4)=10
3y^2+7y-76=10
3y^2+7y-86=0
x=-7±√1081 / 6
=4.31 or -6.65// (corr.to 3sig.fig.)
7)同第2條重複左!
8)4(x-5)^2-49=0
[2(x-5)]^2=49
2(x-5)=±7
x=±7/2 +5
=8.5 or 1.5
9)18y^2-25y-3=0
(2x-3)(9x+1)=0
x=3/2 or -1/9 //
10) 92x(x+3)=161
92x^2+276x-161=0
(46x-23)(2x+7)=0
(2x-1)(2x+7)=0
x=1/2 or -7/2 //
11) x+21/2 =3x^2 /2
2x+21=3x^2
3x^2-2x-21=0
(x-3)(3x+7)=0
x=3 or -7/3 //
12) (y+1)(3y-8)=20
3y^2-5y-8=20
3y^2-5y-28=0
(x-4)(3x+7)=0
x=4 or -7/3 //
13) 6y(y+4)=(2y-3)(y+4)
6y=2y-3
y=-3/4//
14) 2(11z+3)(12z+6)=(7z+8)(12z+6)
22z+6=7z+8
15z=2
z=2/15//
15) 4(z+5)^2=2(z+5)(3z+2)
4z+20=6z+4
16=2z
z=8//
16) (2y+5)^2=(3-4y)^2
2y+5=3-4y
6y=-2
y=-1/3//