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:5.4
Step-by-step explanation:
30% of 18= 18% of 30
10% of 18= 1.8
1.8 times 3=5.4
Answer:
3x+15
Step-by-step explanation:
The factors are
(m-6)(m+6)
Explanation:
Group the first two terms and factor out the common factor:
i.e m(m-6)
Repeat the procedure for terms 3 and 4.
6(m-6)
Regrouping:
m(m-6)+6(m-6)
On factoring out (m-6), we get:
(m-6)(m+6)