1. x2 - 8x + 15
2. x2 + 12x + 20
3. x2 + 4x - 32
4. a2 - 15a + 56
5. y2 + 2xy - 63x2
6. a2 + 11 ab + 30b2
7. 50 + 5a - a2
8. x2 + x + 1
9. 21 - 4x - x2
2006-10-06 07:54:22 · 8 answers · asked by Foxxy 4 in Education & Reference ➔ Homework Help
I actually have the answers to most of the problems and I want to know if it's right and I would like to know where I went wrong if I did do something wrong.
2006-10-06 08:01:00 · update #1
Everything equals 0
2006-10-06 08:04:19 · update #2
I know I have to factor it
so disregard the comment about everything equals 0
2006-10-06 08:05:35 · update #3
if the letter comes before the letter then that means its a "squared" number. Like x-squared
2006-10-06 08:09:20 · update #4
1) x2-8x+15=0
x2-5x-3x+15=0
(x-5)(x-3)=0 so x= 3,5
2)x2+12x+20=0
x2+10x+2x+20=0
(x+10)(x+2)=0 so x= -2,-10
3)x2+4x-32=0
x2+8x-4x-32=0
(x+8)(x-4)=0 so x= 4,-8
4)a2-15a+56=0
a2-7a-8a+56=0
(a-7)(a-8)=0 so a= 7,8
5) y2+2xy-63x2=0
y2+9xy-7xy-63x2=0
(y+9x)(y-7x)=0 so y= -9x,7x or y/x= -9 ,7
6) a2+11ab+30b2=0
a2+5ab+6ab+30b2=0
(a+5b)(a+6b)=0 so a= 6b, -5b or a/b= 6,-7
7) 50+5a-a2=0
50+10a-5a-a2=0
(10-a)(5+a)=0 so a= -5,10
8)x2+x+1=0
x= -1/2 + sqrt3/2 * i using the formula (-b+- sqrt(b2-4ac))/2a
x= -1/2 - sqrt3/2 * i
where i = sqrt(-1)
9)21-4x-x2
21-7x+3x-x2=0
(x+7)(3-x)=0 so x= 3,-7
phew~!...guess thats ur home...good nice way to get over it...
2006-10-06 08:38:10 · answer #1 · answered by just08in 2 · 1⤊ 0⤋
I'll help with a couple, but not the whole list.
You have to factor your polynomials into two binomials. For example:
1. (x - 5)(x - 3) = 0
Set each factor equal to zero and solve.
x=5, x = 3
If the square term is negative, it's easier if you divide every term by -1 before you start:
21. x2 + 4x -21= 0
(x + 7)(x -3) = 0
x= -7, x = 3
Now you really should try the rest on your own.
2006-10-06 08:09:42 · answer #2 · answered by PatsyBee 4 · 1⤊ 0⤋
1. 3, 5
2. -2, 10
3. 4, -8
4. 7, 8
5. no idea
6. no idea
7. -5, 10
8. no real roots
9. 3, -7
2006-10-06 08:14:10 · answer #3 · answered by Anonymous · 1⤊ 0⤋
1. 15 - 6x
2. 20 +14x
3. 6x - 32
4. 56-13a
5. 2xy+2y-126x
6. 11ab+2a+60b
7. 50 + 3a
8. 3x+1
9. 21-6x
2006-10-06 08:06:00 · answer #4 · answered by coool2me 1 · 0⤊ 1⤋
whats the problem equal to? (ex. 2x+4x=24)
2006-10-06 08:03:16 · answer #5 · answered by The infamous bongblaster 4 · 0⤊ 0⤋
i used to when i was doing school, but l been out 15 odd years now and have never used it since sorry. even as a sparky
2006-10-06 08:04:41 · answer #6 · answered by BoChOi 3 · 0⤊ 1⤋
You should ask your teacher if you're on the right track, that's what they're there for or join a math club
2006-10-06 08:02:07 · answer #7 · answered by babysweetvee 3 · 2⤊ 1⤋
thats an unfair way to get homework help by asking for the direct answer,
www.homeworkhelp.com
2006-10-06 07:57:37 · answer #8 · answered by Anonymous · 0⤊ 2⤋