Let x be the first angle
y be the second angle
z be the third angle.
for the second angle, complementary angles are angles sum are 90 degrees
y = 2 ( 90 - x )
y = 180 - 2x
2x + y = 180
for the third angle, supplementary angles are angles sum are 180 degrees
z = 0.5( 180 - x )
z = 90 - 0.5x
0.5x + z = 90
then the sum of a triangle is 180
x + y + z = 180
so x = 60
y = 60
z = 60
Answer:
-9
Step-by-step explanation:
The change she receive = 20-6.43= 13.57$
I believe this is right
Move the decimal over two places so so it becomes .28
Then divide 448 by .28
Which is equaled to 1600
Move the decimal over two places so 24% becomes .24
Then multiply .24 by 1600
And the answer is 384
(Might be wrong sorry)
Answer:
x = sqrt(433/64) - 7/8 and x = -sqrt(433/64) - 7/8 So there are two. Let me know if there's something you don't understand.
Step-by-step explanation:
First you want to get them into the form where just y is on one side.
5-y=x^2+x
-y=x^2+x-5
y = -x^2 - x + 5
y+1 = 3/4x
y = 3/4x - 1
Let me know if you don't get how I did that.
To find where they intersect you just set them equal to each other and solve for x.
-x^2 - x + 5 = 3/4x - 1
Before you go solving you are going to want to avoid multiplying and dividing. Especially dividing here. if you divide something by (x-a) you make it so a cannot be used. take 1 for instance. graphing 1 is just a horizontal line at y=1. If you divide it by (x-a) in particular lets say (x-1) if you try and solve for x=1 you get 1/0 and you can't divide by 0. If you graph it on a calculator or computer you'll see the graph doesn't exist at x=1 either.
So yeah, no multiplying or dividing. So we turn this into a quadratic.
-x^2 - x + 5 = 3/4x - 1
-x + 5 = x^2 + 3/4x - 1
5 = x^2 + 7/4x - 1
0 = x^2 + 7/4x - 6
There are a few ways to solve but I am going to complete the square. If you don't understand how to solve it let me know and I will more specifically walk through it.
(x + 7/8)^2 - 433/64 = 0
(x + 7/8)^2 = 433/64
x + 7/8 = +/- sqrt(433/64)
x = +/- sqrt(433/64) - 7/8
So there are two answers here. Positive sqrt(433/64) - 7/8 and negative sqrt(433/64) - 7/8 Or approximately 1.726 and -3.476 respectively. To check try plugging these into the original two functions y = -x^2 - x + 5 and y = 3/4x-1 and make sure they give the same answer.
Let me know again if there's something you don't get. When oing intersections though you set the two equations equal to each other and solve for x however you can.
