a)
I don't know what kind of diagram it wants.....but we can calculate the percenteges like this:
We can replace the % sign with / 100
And we can replace the word "of" with *
So.....
i)
ii)
iii)
iv) | __ | 400% of 240 = 400/100 * 240 = 4 * 240 = 960
40% of 240 = 40/100 * 240 = 4/10 * 240 = ?
4% of 240 = 4/100 * 240 = ?
0.4% of 240 = 0.4/100 * 240 = ? |
Can you finish those?
After you get the answers for these, you might notice the pattern that they are talking about in part b.
.
1 million__=__ | . 1 . | . 0 . | . 0 . | . 0 . | . 0 . | . 0 . | . 0 . | __=__1 * 106 |
1 | 2 | 3 | 4 | 5 | 6 |
1 trillion__=__ | . 1 . | . 0 . | . 0 . | . 0 . | . 0 . | . 0 . | . 0 . | . 0 . | . 0 . | . 0 . | . 0 . | . 0 . | . 0 . | __=__1 * 1012 |
1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 |
1 googol =__ | . 1 . | . 0 . | . 0 . | . 0 . | . 0 . | . . . . . | . 0 . | . 0 . | . 0 . | . 0 . | ___=___1 * 10? |
1 | 2 | 3 | 4 | 97 | 98 | 99 | 100 |
We are given:
A = (4, 1)
B = (6, 2)
C = (-1, 2)
And we can let:
P = (x, y)
By the Pythagorean Theorem/distance formula we can say:
PA2 = (x - 4)2 + (y - 1)2
PB2 = (x - 6)2 + (y - 2)2
PC2 = (x + 1)2 + (y - 2)2
Then....
PA2 + PB2 + PC2 = (x - 4)2 + (y - 1)2 + (x - 6)2 + (y - 2)2 + (x + 1)2 + (y - 2)2
Expand each term, then combine like terms to get:
PA2 + PB2 + PC2 = 3x2 - 18x + 3y2 - 10y + 62
(I used this to do that because I am lazy.)
Next we want to get the expression on the right side of the equation into the form:
3PQ2 + k
which is:
3[ (x - something)2 + (y - something)2 ] + k
To do that, we need to complete the squares of the x terms and the y terms.
PA2 + PB2 + PC2 = 3(x2 - 6x) + 3(y2 - \(\frac{10}{3}\)y) + 62
PA2 + PB2 + PC2 = 3(x2 - 6x + 9 - 9) + 3(y2 - \(\frac{10}{3}\)y + \(\frac{25}{9}\) - \(\frac{25}{9}\)) + 62
PA2 + PB2 + PC2 = 3( (x - 3)2 - 9) + 3( (y - \(\frac53\))2 - \(\frac{25}{9}\)) + 62
PA2 + PB2 + PC2 = 3(x - 3)2 - 27 + 3(y - \(\frac53\))2 - \(\frac{25}{3}\) + 62
PA2 + PB2 + PC2 = 3(x - 3)2 + 3(y - \(\frac53\))2 - \(\frac{25}{3}\) + 62 - 27
PA2 + PB2 + PC2 = 3[ (x - 3)2 + (y - \(\frac53\))2 ] - \(\frac{25}{3}\) + 62 - 27
PA2 + PB2 + PC2 = 3[ (x - 3)2 + (y - \(\frac53\))2 ] + \(\frac{80}{3}\)
(Check)
Now it is in the desired form, and so we can pick out that k = \(\frac{80}{3}\)
BTW, I came across this answer. It works out a bit more cleanly if A = (4, -1). Just wanted to mention this in case that is what you meant.