9514 1404 393
Answer:
C. 1.2
Step-by-step explanation:
A probability is always in the range 0 to 1, inclusive. The value 1.2 cannot be a probability.
A <em>difference of squares</em> is exactly what it suggests - the difference between two perfect squares. 25 - 9, 4 - 1, x² - 25, and 125 - b² are just a few examples. Differences of squares factor very nicely, too. For any difference of squares x² - y²:
x² - y² = (x + y)(x - y)
We can see that this is true by taking the right side of the equation and distributing:
(x + y)(x - y) = (x + y) · x + (x + y) · (-y) = x² + xy - xy - y² = x² - y²
We notice in our given expression that 36 is a perfect square - namely, 6². We want the expression x² + ?x - 36 to look like x² - 6², which we can accomplish if we replace the question mark with a 0.
-9x + b
-9(-5) + 4
45 + 4
49
1. If a and b vary inversely and b = 8 when a = 6:
b = k/ a
8 = k / 6
k = 6 * 8
k = 48
Function is:
b = 48 / a
2. When a = 30:
b = 48 / 30 = 8/5
b = 1.6