00:01
Okay, so here's the deal.
00:03
I thought i was recording and i wasn't, but i really would rather not go back and redo all these.
00:08
So i'm just going to explain to you what i did while i thought i was recording and i wasn't.
00:12
So i started out with the first one, divide on a, dividing everything by two, just to get rid of that coefficient of the two.
00:18
That left me was z squared minus 8z minus 884, equals zero.
00:24
Then i completed the square to get my perfect trunch square here, which gave me 16, which factors to z minus 4 squared.
00:34
And then since i added 16 to one side, i had to add it to the other, and that gave me 900.
00:39
Took the square root of both sides, so z minus 4 equals plus or minus 30.
00:43
So i set it both equal, i did z minus 4 equals 30 and z minus 4 equals negative 30, and i got 34 and 26.
00:52
On the next one, move the 9, move the net 10 over made at negative 10, completed the square, found that to be 9 on both sides, and that factor to x plus 3 squared.
01:02
Negative 10 plus 9 is negative 1.
01:05
Subtrak 3 on both sides.
01:06
So i got negative 3 plus i and negative 3 minus i.
01:10
The next one said use the quadratic formula.
01:13
So i had to put it in standard form first.
01:15
So 3t squared minus 12t plus 15 equals 0.
01:19
So this is my quadratic formula where i plugged in all the pieces.
01:23
And i found t to equal to plus i and two minus.
01:30
I.
01:32
Next, on b, i cross -multiplied.
01:35
When i cross -multiplied, i got 4v minus 16 equals v squared minus 6v, and then i moved everything over to get it equal to zero and had v squared minus 10b plus 16.
01:48
Plug that into the quadratic formula.
01:52
So, and i found it to equal 10 plus or minus 6 over 2, so 10 plus 6 over 2 is 8, and 10 minus 6 over 2.
02:01
Or two is two.
02:03
So these were my answers for v.
02:05
So v equal eight and that and two.
02:08
Now here what i did is i wanted to get rid of this w first.
02:13
So instead of distributing and then going back and factoring all that good jazz, i just took the w and divided by w.
02:20
But when i do that, i have to account for w equals zero.
02:24
So there is going to be a factor of w equals zero...