Answer:
x + y = 20
Step-by-step explanation:
Let the amount collected by Alexa = $x
& the amount collected by Daniel = $y
Total amount collected = $20
Therefore,
x + y = 20
Step-by-step explanation:
-10 + ( -10)
= -10 - 10
= - 20
Hope it will help .
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:
The least score the student can get is 71 to get an overall B average at the end of the year.
Step-by-step explanation:
Let the score she needs to get be = x
We now have to take the mean of all the five subjects <em>(including x)</em> and equate it to the least score she can have to get a B grade.
Let us take the least score the student needs to get a B grade to be 85
Mean of all 5 scores =
The least score the student can get is 71 to get an overall B average at the end of the year.
Answer:
67 units^2
Step-by-step explanation:
The surface area of the prism is found by
SA = 2 ( lw+lh + wh)
= 2 ( 5*1.5+ 4*1.5 + 5*4)
= 2 ( 7.5+6+20)
= 2 (33.5)
= 67
