Your answer is D. 16x² - 56xy + 49y².
A perfect square trinomial is the result of a squared binomial, like (a + b)². Using this example, the perfect square trinomial would be a² + 2ab + b², as that is what you get when you expand the brackets.
Therefore, to determine which of these is a perfect square trinomial, we have to see if it can be factorised into the form (a + b)².
I did this by first square rooting the 16x² and 49y² to get 4x and 7y as our two terms in the brackets. We automatically know the answer isn't A or B as you cannot have a negative square number.
Now that we know the brackets are (4x + 7y)², we can expand to find out what the middle term is, so:
(4x + 7y)(4x + 7y)
= 16x² + (7y × 4x) + (7y × 4x) + 49y²
= 16x² + 28xy + 28xy + 49y²
= 16x² + 56xy + 49y².
So we know that the middle number is 56xy. Now we assumed that it was (4x + 7y)², but the same 16x² and 49y² can also be formed by (4x - 7y)², and expanding this bracket turns the +56xy into -56xy, forming option D, 16x² - 56xy + 49y².
I hope this helps!
Answer:
C
Step-by-step explanation:
You can use a calculator and put is where I’d can tell you the answer
A. Make a list of the first 10 integers that come to your head should NOT be used
Answer:
measure of larger angle = 240 degrees
measure of each of the smaller angles = 120 degrees
Explanation:
In any polygon, the sum of measures of interior angles can be calculated using the following rule:
sum of interior angles = (n-2)*180 where n is the number of sides
Now, for an octagon, n=8, this means that:
sum of measures of interior angles = (8-2)*180 = 1080°
An octagon has 8 interior angles, one of which is twice the measure of the others.
Assume that each of the 7 smaller angles is x degrees and that the larger angle is 2x degrees
Computing their summation, we will find that:
x + x + x + x + x + x + x + 2x = 1080
9x = 1080
x = 120
This means that:
each one of the smaller angles = x = 120 degrees
the larger angle = 2x = 2 * 120 = 240 degrees
Hope this helps :)
