Please help 20 points

1 answer:

3 0

Four angles must add up to 360.

∠A+∠B+∠C+∠D=360 (5/2x+30)+(7/2x+40)+(9/2x+10)+(5/2x+20)=360 26/2x + 100 = 360 13x = 260 x = 20. To solve for ∠C, plug x back in: ∠C = 9/2x+10 = 9/2*20+10 = 100

You might be interested in

1v1 lol i'm a girl the code is za9nja

Naya [18.7K]

Answer:

i thought you was a guy ?

Step-by-step explanation:

3 0

3 years ago

A motorcyclist rides 976 miles, using 30.5 gallons of gasoline. What is the mileage, in miles per gallon

IgorC [24]

D 32 miles to the gallon
976 divided by 30.5 equals 32

4 0

2 years ago

Read 2 more answers

dale is driving to Miami. suppose that the distance (in miles) is a linear function of his total driving time (in minutes). dale

nexus9112 [7]

Considering there is a function (relationship) and that it is linear, the distance will change proportionally to time constantly. In other words, we are taking the speed to be constant throughout the journey.
If we let:
t = time (min's) driving
d = distance (miles) from destination
Then we can represent the above information as:
t = 40: d = 59
t = 52: d = 50
If we think of this as a graph, we can think of the x-axis representing time and the y-axis representing the distance to the destination. Being linear, the function will be a line, i.e. it will have a constant gradient. If you were plot the two points inferred from the information and connect the two dots, you will get a declining line (one with a negative gradient) representing the inversely proportional relationship or equally, the negative correlation between the time driving and the distance to the destination. The equation of this line will be the linear function that relates time and the distance to the destination. To find this linear function, we do as follows:

Find the gradient (m) of the line:
m = Δy/Δx
In this case, the x-values are t-values and our y-values are d-values, so:
Δy = Δd
= 50 - 59
= -9
Δx = Δt
= 52 - 40
= 12
m = -9/12 = -3/4
Note: m is equivalent to speed with units: d/t

Use formula to find function and rearrange to give it in the desired format:
y - y₁ = m(x - x₁)
d - 50 = -3/4(t - 52)
4d - 200 = -3t + 156
4d + 3t - 356 = 0

Let t = 70 to find d at the time:
4d + 3(70) - 356 = 0
4d + 210 - 356 = 0
4d - 146 = 0
4d = 146
d = 73/2 = 36.5 miles

So after 70 min's of driving, Dale will be 36.5 miles from his destination.

3 0

3 years ago

MERRY CHRISTMAS!!! pls help me with this and you will get the Christmas present you wanted!!plus brainlist lol

scoundrel [369]

Answer:

0.2

Hope this helps!

xoxo,

cafeology

7 0

3 years ago

What are the vertex focus and directrix of a parabola with equation x=y^2+14y-2

zimovet [89]

This is a sideways opening parabola, opening to the right to be more specific, since the leading coefficient is a positive 1. The rule for a focus and a directrix is that they are the same number of units from the vertex (in other words, the vertex is dead center between them), and that the vertex is on the same axis that the focus is. We need to find the vertex then to determine what the focus and the directrix are. We will complete the square on that to find the vertex. Begin by setting it equal to 0, then move the 2 over by addition to get $y^2+14y=2$ . Now we will complete the square on the y terms. Take half the linear term, square it, and add it to both sides. Our linear term is 14. Half of 14 is 7, and 7 squared is 49. So we add 49 to both sides. $y^2+14y+49=2+49$ , which of course simplifies to $y^2+14y+49=51$ . The purpose of this is to find the k coodinate of the vertex which will be revealed when we write the perfect square binomial we created during this process: $(y+7)^2=51$ . Moving the 51 back over by subtraction gives us $(y+7)^2-51=x$ . The vertex then is (-51,-7). The formula to find the focus using this vertex is $(h+ \frac{1}{4a},k)$ . As I stated quite a while ago, the leading coefficient on our parabola was a +1 so our "a" value is 1, and the focus is then found in $(-51+ \frac{1}{4},-7)$ which simplifies to $(-50.75, -7)$ . If the vertex is (-51, -7) and the focus is (-50.75, -7), then the distance between them is 1/4, or .25. That means that the directrix is also .25 units from the vertex, but in the other direction. Our directrix is a vertical line, and it will have the equaion x = -51.25. Summing up, your focus is (-50.75, -7) and your directrix is x = -51.25

7 0

3 years ago