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!
For the first one,
you multiply 5x and -5 to get -25.
Then you move the constant to the right and change the sign to get 3x= -21 +25.
Calculate the sum of -21+25 to get 4.
Divide both sides of the equation by 3 to get x=4/3.
So then your final answer is x=4
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3
For the second one,
Distribute 7 through the parentheses to get 14x + 14+8=120
The you add 14+8 to get 22. Your equation should be 14x+22=120
Move the constant to the right side and change its sign to get 14x=120-22
Subtract 120-22 to get 98. Now your equation should be 14x=98
Divide both sides of the equation by 14 to get x=7.
Your finial answer for the second one should be x=7.
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I hope this made sense.
the stunning men has be fly for a 1 min
Answer:
answer is C
Step-by-step explanation:
Because it gives clear distribution process.