Answer:
C
Step-by-step explanation:
49x² + 28xy + 4y² ← is a perfect square of the form
(ax + by)² = a²x² + 2abxy + b²y²
49 = 7² ⇒ a = 7 and 4 = 2² ⇒ b = 2
2ab = 2 × 7 × 2 = 28
Hence
49x² + 28xy + 4y² = (7x + 2y)²
with factor 7x + 2y ⇒ C
For this, we use simultaneous equations. Let George's page be g, Charlie's be c and Bill's page be b.
First, <span>George's page contains twice as many type words as Bill's.
Thus, g = 2b.
</span><span>Second, Bill's page contains 50 fewer words than Charlie's page.
Thus, b = c - 50.
</span>If each person can type 60 words per minute, after one minute (i.e. when 60 more words have been typed) <span>the difference between twice the number of words on bills page and the number of words on Charlie's page is 210.
We can express that as 2b - c = 210.
Now we need to find b, since it represents Bill's page.
We can substitute b for (c - 50) since b = c - 50, into the equation 2b - c = 210. This makes it 2(c - 50) - c = 210.
We can expand this to 2c - 100 - c = 210.
We can simplify this to c - 100 = 210.
Add 100 to both sides.
c - 100 + 100 = 210 + 100
Then simplify: c = 210 + 100 = 310.
Now that we know c, we can use the first equation to find b.
b = c - 50 = 310 - 50 = 260.
260 is your answer. I don't know where George comes into it. Maybe it's a red herring!</span>
Answer:
s = 6, r = 8 or s = 4, r = 7
Step-by-step explanation:
2r - s = 10
2r = 10 + s
r = 5 + s/2 --(1)
rs - s^2 = 12 --(2)
sub (1) into (2):
(5 + s/2)s - s^2 = 12
5s + 0.5s^2 - s^2 = 12
-0.5s^2 + 5s - 12 = 0
s^2 - 10s + 24 = 0
(s - 6)(s - 4) = 0
therefore s = 6 or s = 4
when s = 6, r = 8 and when s = 4, r = 7
if you would like to discover more about simultaneous equations, you can have a look at my Instagram page (learntionary). I'll be posting mathematics related stuff there and some of my notes (simultaneous enq notes are already posted!)
One value: would be a single valued function, or just one answer.
Real numbers would be: natural numbers, whole numbers, integers, rational numbers (fractions and repeating or terminating decimals), and irrational numbers.
No solution: there is no answer to the question.
