You need help with all of them or one in specific?
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:
m= 4/3
Step-by-step explanation:
Answer:
14800
Step-by-step explanation:
Area of trapezoid = 
Using the formula above, our equation will look like this:

145 + 225 = 370
370/2 = 185
185 * 80 = 14800
PLZ GIVE BRAINLIEST
Answer:
2/5
Step-by-step explanation:
We can find the slope of a line given two points by using
m =(y2-y1)/(x2-x1)
= (7-5)/(9-4)
= 2/5