Step-by-step explanation:
#1.
(a + 2b)²
<em>Using identity (x + y)² = x² + 2xy + y², we get:</em>
= (a)² + (2b)² + 2 × (a) × (2b)
= a² + 4b² + 4ab
= a² + 4ab + 4b² Ans.
#2.
(5x - 3y)²
<em>Using identity (a - b)² = a² - 2ab + b², we get:</em>
= (5x)² + (3y)² - 2 × (5x) × (3y)
= 25x² + 9y² - 30xy
= 25x² - 30xy + 9y² Ans.
#3.
(3a + 4)(3a - 4)(9a² + 16)
<em>Using identity (x + y)(x - y) = x² - y², we get:</em>
= [(3a)² - (4)²][9a² + 16]
= (9a² - 16)(9a² + 16)
= (9a²)² - (16)²
= 81a⁴ - 256 Ans.
Answer:
C = (13.75 * B * H)/3750
Step-by-step explanation:
The area of a triangle is represented by the equation A = 1/2 * B * H
Every time another 3750 square feet is covered, $27.50 is spent. So, we can represent the cost using the equation C = A/3750 * 27.50
Plugging in the base and height, C = (1/2 * B * H * 27.50)/3750
C = (13.75 * B * H)/3750
Answer:
A. because it earns interest
Step-by-step explanation:
The interest rate is the gaining that you make for keeping your money in the bank. Suppose you have $100 and the bank offers you a 5% annually interest rate. The rate (5%) means that your money will earn five percent of the value each year, so after the first year you will earn (5%)*($100) = $5 of interest just for keeping your money in your savings account. Therefore, your money will grow overtime because it is earning interest. Remember that interest can be compound (over periods) or simple (like our example).
Since the price is now 15% less you would first find what 15% of 25 is by using 25*.15 and get 3.25 then you subtract that from 25 and get 25-3.25= $21.75
