I believe the answer is -51+60 because it equals -9. And -51-(-60) is 9.
Now cos⁻¹(0.7) is about 45.6°, that's on the first quadrant.
keep in mind that the inverse cosine function has a range of [0, 180°], so any angles it will spit out, will be on either the I quadrant where cosine is positive or the II quadrant, where cosine is negative.
however, 45.6° has a twin, she's at the IV quadrant, where cosine is also positive, and that'd be 360° - 45.6°, or 314.4°.
now, those are the first two, but we have been only working on the [0, 360°] range.... but we can simply go around the circle many times over up to 720° or 72000000000° if we so wish, so let's go just one more time around the circle to find the other fellows.
360° + 45.6° is a full circle and 45.6° more, that will give us the other angle, also in the first quadrant, but after a full cycle, at 405.6°.
then to find her twin on the IV quadrant, we simply keep on going, and that'd be at 360° + 360° - 45.6°, 674.4°.
and you can keep on going around the circle, but only four are needed this time only.
Answer: A. 35+1
B. 20+ 5z
C. 4 + 12
Step-by-step explanation:
This is just using the distributive property which is like foiling
Answer:
y=7
Step-by-step explanation:
We have two numbers,
x
,
y
. We know two things about them:
2
x
+
y
=
25
3
x
−
y
=
20
Let's add these two equations together which will cancel the
y
:
5
x
+
0
y
=
45
x
=
45
5
=
9
We can now substitute in the
x
value into one of the original equations (I'll do both) to get to
y
:
2
x
+
y
=
25
2
(
9
)
+
y
=
25
18
+
y
=
25
y
=
7
3
x
−
y
=
20
3
(
9
)
−
y
=
20
27
−
y
=
20
Using a 1-sample z-interval for the population proportion with confidence level 0.997, the sample probability is 0.69 with margin of error of 0.16, so between 0.69+0.16=0.85 of the population and 0.69-0.16=0.53 of the population prefers coffee. 84% and 54% are the correct answers.
