1. (3 + xz)(–3 + xz)
2. (y² – xy)(y² + xy)
3. (64y2 + x2)(–x2 + 64y2)
Explanation
The difference of 2 squares is in the form (a+b)(a-c).
(3 + xz)(–3 + xz) = (3 + xz)(xz -3)
= (xz + 3)(xz - 3)
= x²y²-3xy+3xy-9
=x²y² - 3²
(y² – xy)(y² + xy) = y⁴+xy³-xy³-x²y²
= y⁴ - x²y²
(64y2 + x2)(–x2 + 64y2)= (64y²+x²)(64y²-x²)
= 4096y⁴-64y²x²+64y²x²-x⁴
= 4096y⁴ - x⁴
Answer:
87.9
Step-by-step explanation:
Use a calculator or table to find the z-score that corresponds to 25%.
P(Z < z) = 0.25
z = -0.675
Now find the value that corresponds to that z score.
z = (x − μ) / σ
-0.675 = (x − 101.3) / 19.9
x = 87.9
Answer:
Sabrina is at a higher elevation.
Step-by-step explanation:
She has dropped less than Ben, so she is higher up.
Answer: The tree was 27 feet tall
Step-by-step Explanation: First of all Sally was standing 30 feet away from the tree and she looks up at an angle of elevation of 38 degrees to the top of the tree. With this bit of information we can determine that a right angled triangle has been formed with the reference angle as 38 degrees, the side facing it as h (the height of the tree) and the adjacent side as 30. We shall apply the trigonometric ratio as follows;
Tan 38 = opposite/adjacent
Tan 38 = h/30
0.7813 = h/30
0.7813 x 30 = h
23.4 = h
We remember at this point that Sally’s eyes were 4 feet above the ground. What we have just calculated is the height of the tree from “4 feet above the ground” (where her eyes were). Hence the actual height of the tree is calculated as 23.4 plus 4 which gives us 27.4
Therefore the tree was 27 feet tall (approximately to the nearest foot)
Answer:
b) $475
Step-by-step explanation:
if it has a diameter of 22 feet, that means it has a radius of 11 feet
the formula of the area of a circle is πr². so square the radius and you will get 121, multiply that by π and you get 380
Now we know the area is 380 square feet, so multiply that by $1.25 and the answer is $475
