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!
Indirect material cost: y
explained by units produced: x
Linear regression. Cost estimation equation: y=mx+b
Constant: b=$15,640
Standard error of y estimate=$3,600
r^2=0.7704
Number of observations: n=22
x coeffient: m=11.25
Standard error of x coefficient=2.19
m=11.25, b=15,640 → y=11.25x+15,640
Answer: The cost estimation equation is y=11.25x+15,640
To estimate this I find it easy to turn the fractions into decimals and then you can easily estimate. To turn a fraction into a decimal divide the numerator by the denominator.
Answer:
The value of this expression is -35.
Step-by-step explanation:
Let's use the order of operations (PEMDAS), to solve this problem.
In conclusion, the value of this expression is -35. Hope this helped :D
