Question

will fan and medal.. I REALLY NEED HELP
The sum of the measures of angle X and Y is 90. If the measures of angle X is 30 less than twice the measure of angle Y, what is the measure of angle X?
A. 20
B. 35
C. 50
D.65

Answer 1

Let x and y be the measures of angles X and Y.

The sum of the measures of angle X and Y is 90.
So, x = y = 90

angle X is 30 less than twice the measure of angle Y,
So, x = 2y -30

Answer 2

x + y = 90
x = 2y -30
substitute x in the first equation

(2y-30) + y = 90
solve for y, then plug in y in the first equation to find x

Answer 3

i think its x= 30-2y actually.

Answer 4

so then how do i get x from there?

Answer 5

well they give you 2 equations to work with.
one is x + y= 90
one is x = 30-2y

Answer 6

x + y = 90 ---> x = 90 - y
x = 2y -30---->x = 2y-30
-----------

Answer 7

plug in the 2nd equation into the first equation, then solve for y,
after you solve for y you can solve for x by doing 90-y = x

Answer 8

.....so what is x?

Answer 9

90-y = 2y - 30
y = 40

Subtract 40 from 90 to get x.

Answer 10

you can't expect us to do your hw

Answer 11

40-90=-50

Answer 12

is that x?-50?

Answer 13

90-40 not 40 - 90

Answer 14

so just 50?

Answer 15

Can you help with this one?
the yearbook club is having a bake sale to raise money for the senior class. LArge cupcakes are sold for 1.25 and small cupcakes are .75. If 105 cupcakes were sold for a total amount of 109.75, how many large cupcakes did the yearbook club sell?

Answer 16

@Directrix

Answer 17

@yoonlim19

Answer 18

Let L and S be the number of large and small cupcakes sold, respectively.

Then, L + S= 105

Answer 19

okay so then how do i figure out how many large cupcakes were sold?

Answer 20

this question confuses me so much..D:

Answer 21

1.25L + .75S = 109.75
L + S= 105
----------------------

Answer 22

The task is to solve those two equations simultaneously.

Answer 23

okay. i know that but how do i use that to find out how many large cupcakes were sold

Answer 24

You use Algebra.

1.25L + .75S = 109.75 ----> multiply each member by 100
L + S= 105

Answer 25

125L +75S =109.75
L + S= 105
---------------

Answer 26

125L +75S =109.75

L + S= 105 --> L = 105 - S

Answer 27

confusion continues..

Answer 28

okayy... so how do i get the amount of cupcakes with that?

Answer 29

125L +75S =10975
L + S= 105 --> L = 105 - S

Solve these two equations in two unknowns simultaneously.
Use the substitution method.

Answer 30

Can you do that and like explain what your doing to get the answer so i can see how to do it?

Answer 31

Did you follow to this point:

125L +75S =10975
L + S= 105 --> L = 105 - S

Answer 32

yeah

Answer 33

125L +75S =10975
125(105 -S) = 10975

Answer 34

okay...

Answer 35

You multiply this --> 125(105 -S) and post what you get, okay?

Answer 36

what is s?

Answer 37

.75?

Answer 38

Just call it S

Answer 39

13125s?

Answer 40

125(105 -S) = 13125 - 125S

You have to use the Distributive Property

Answer 41

okay..

Answer 42

13000s?

Answer 43

125(105 -S) = 10975
13125 - 125S = 10975

Answer 44

so whats L?

Answer 45

What is 10975 - 13125 = ?

Answer 46

-2150 ^

Answer 47

- 125*S = -1250

Answer 48

What is -1250 divided by -125 =

Answer 49

10

Answer 50

Something has run amok here because look at the Wolf's work:

http://www.wolframalpha.com/input/?i=%28125L+%2B75S+%3D10975%29+and+%28L+%2B+S%3D+105%29

Answer 51

that helps alot thanks

Answer 52

The Wolf has L = 62 and S = 43 so we have to back up and find where our error is.

Answer 53

The equations are correct but somewhere there is an error in our arithmetic.

Answer 54

ok well ill look at that website.. thanks:D

Answer 55

Okay.