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3 years ago

Please help Ill give brainiest!

Mathematics

2 answers:

makkiz [27]3 years ago

7 0

Answer:

H is the best answer.

Step-by-step explanation:

Isabell and her three sisters means that there is 4 people.

Since C equals the amount each sister spends it has to be less that 60.

(<) this symbole shows that the money the sisters spent is less than 60.

This means that 4c<60 is the best answer.

Sliva [168]3 years ago

4 0

Answer:

H. 4c <60

Step-by-step explanation:

You might be interested in

Find the value of Y to nearest tenth... <br> cos 64degrees = y/8

Rzqust [24]

Step-by-step explanation:

what is the problem ? this is very straight forward with a calculator :

cos(64°) = y/8

y = 8×cos(64°) = 8×0.438371147... = 3.506969174... ≈

≈ 3.5

4 0

2 years ago

PLEASE HELP

sweet [91]

To model and solve our situation we are going to use the equation: $s= \frac{d}{t}$
where
$s$ is speed
$d$ is distance
$t$ is time

1. We know that the distance between the cities is 2400 miles, so $d=2400$ . We also know that the speed of the plane is 450 mi/h. Since we don't know the speed of the air, $S_{a}=?$ . We don't know how much the westward trip takes, so $t_{w}=?$ , and we also don't know how much the eastward trip takes, so $t_{e}=?$ .

Going westward. Here the plane is flying against the air, so we need to subtract the speed of the air from the speed of the plane:
$450-S_{a}= \frac{2400}{t_{w} }$
Going eastward. Here the plane is flying with the the air, so we need to add the speed of the air to the speed of the plane:
$450+S_{a}= \frac{2400}{t_{e} }$

2. We know for our problem that the round trip takes 11 hours; so the total time of the trip is 11, $t_{t}=11$ . Notice that we also know that the total time of the trip equals time of the tip going westward plus time of the trip going eastward, so $t_{t}=t_{w}+t_{e}$ . Since we know that the total trip takes 11 hours, we can replace that value in our total time equation and solve for $t_{w}$ :
$11=t_{w}+t_{e}$
$t_{w}=11-t_{e}$

Now we can replace $t_{w}$ in our going westward equation to model our round trip with a system of equations:
$450-S_{a}= \frac{2400}{t_{w}}$
$450-S_{a}= \frac{2400}{11-t_{e} }$ equation (1)
$450+S_{a}= \frac{2400}{t_{e}}$ equation (2)

3. To solve our system of equations, we are going to solve for $t_{e}$ in equations (1) (2):

From equation (1)
$450-S_{a}= \frac{2400}{11-t_{e} }$
$11-t_{e}= \frac{2400}{450-S_{a} }$
$-t_{e}= \frac{2400}{450-S_{a} } -11$
$t_{e}=11- \frac{2400}{450-S_{a} }$
$t_{e}= \frac{4950-11S_{a} -2400}{450-S_{a} }$
$t_{e}= \frac{2550-11S_{a} }{450-S_{a} }$ equation (3)

From equation (2):
$450+S_{a}= \frac{2400}{t_{e} }$
$t_{e}= \frac{2400}{450+S_{a} }$ equation (4)

Replacing (4) in (3)
$\frac{2400}{450+S_{a}} = \frac{2550-11S_{a}}{450-S_{a} }$
Now, we can solve for $S_{a}$ to find the speed of the wind:
$2400(450-S_{a})=(450+S_{a})(2550-11S_{a})$
$1080000-2400S_{a}=1147500-4950S_{a}+2550S_{a}-11(S_{a})^{2}$
$11(S_{a})^{2}-67500=0$
$11(S_{a})^{2}=67500$
$(S_{a})^{2}= \frac{67500}{11}$
$S_{a}=+/- \sqrt{ \frac{67500}{11} }$
Since speed cannot be negative, the solution of our equation is:
$S_{a}= \sqrt{ \frac{67500}{11} }$
$S_{a}=78.33$

We can conclude that the speed of the wind is 78 mph.

3 0

4 years ago

Someone please help me it's worth 35 points

Zigmanuir [339]

Question 1)
I assume it asks about the circumference (of only the circle arc)
C=r*2*pi
r=2
-> C=4pi

1 Quarter only of the circle: C/4=pi=3.1

if it's the perimeter of the shape then you need to add the two 2in sides

C=3.1+2*2=7.1

2)
C=r*2*pi, but not a full circle, only semi-> divide by 2-> C=r*pi
r=30
C=30pi=94.2

3)
the radius of the semicircle is 6/2=3mm
semicircle C=r*pi=3pi

add the rectangle perimeter
3pi+2*3+6=12+3pi=21.4

4)
C=2r*pi
insert 2r=d=12
C=12pi=37.7

5)
C=2r*pi
r=10
C=20*pi~62.8

3 rotations of the wheel->
distance=C*3=188.4

4 0

3 years ago

Someone please help me ?

Alex777 [14]

Answer: Choice A

This is a 45-45-90 triangle so the hypotenuse is sqrt(2) times longer than the leg

hypotenuse = leg*sqrt(2)
hypotenuse = 12*sqrt(2)

3 0

4 years ago

Subtract.<br> (-9r - 3) - (7r - 1)<br> Submit

harina [27]

Answer:

-16r -2

Step-by-step explanation:

plz brainliest :)

do you want an explanation?

8 0

3 years ago