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:
x = 1
Step-by-step explanation:
To solve for a variable, you need to get the variable on one side of the equation, and by itself.
4x + 5 = x + 8
4x = x + 3 --- subtract 5 from both sides
3x = 3 --- subtract x from both sides
x = 1 --- divide both sides by 3
45/x =15/100
Cross multiply
15x=4500
Divide both sides by 15
X=300
300 total cars on parking lot
I think this may be multiplication so 5 times 10 equls50
Answer:
Step-by-step explanation:
In order to figure out how much money was left in the account after the interest was withdrawn, we have to first find out how much money was initially deposited to earn that amount of interest! The means to find that initial investment is found in the simple interest formula
prt = I, where
p is the initial investement,
r is the interest rate in decimal form,
t is the time in years, and
I is the interest earned. Notice that we have all those things but the p.
Filling in:
p(.0425)(4) = 2380 and
.17p = 2380 so
p = 14000
That means that 14000 was initially invested. If the depositor withdrew the 2380, then
14000 - 2380 is the amount left in the account, namely, $11620
