Question

How can I find the values of x and y in an isosceles triangle in the drawing I will show...please help!!!

Answer 1

Please help!

Answer 2

4y is the vertex angle and 2x + y and 79- x are the base angles

Answer 3

Set 2x + y = 79- x

Answer 4

@middi1997 Helloo..o!

Answer 5

hi

Answer 6

2x + y = 79- x

Answer 7

Gather x and y terms to the left side, will you!

Answer 8

ok h/o

Answer 9

I got 3x + y = 79

Answer 10

Then the second equation is total of angles in triangle = .... degree?

Answer 11

um I do not understand

Answer 12

oh sorry its 180 degrees

Answer 13

Yup :)
Now add all these 3 angles together, can you?

Answer 14

well what do i do about 79
would it be 3x + 5y = 180

Answer 15

( 2x +y) + ( 79 -x ) + 4y = ...?

Answer 16

I mean it's not 3x!

Answer 17

= 180
but what do we do with the 3x + y

Answer 18

wait im confused sorry

Answer 19

Focus on the left side first!

Answer 20

so it starts of like this:
2x + y = 79 - x
2x + y + x = 79 - x + x
3x + y + 79
and now im confused

Answer 21

This is the first equation, correct!

Answer 22

But we need the second one to solve for both x, y!

Answer 23

so the second one is 2x +y) + ( 79 -x ) + 4y? but why

Answer 24

So we make the second one from total of angles = 180!

Answer 25

As a thumb rule, when we have 2 unknowns, we need 2 equations !

Answer 26

ok so the result of the second equation i have so far is x + 5y = 101

Answer 27

Correct now :)
3x + y = 79 (1)
x + 5y = 101 (2)
Can you solve system of 2 equations to find x, y?

Answer 28

I don't think I am that advanced yet

Answer 29

gaah im in geometry but i never had algebra 1 or 2

Answer 30

oh ok do you know a short way to explain system of equations

Answer 31

However, don't be discourage, I'll show you if you want to learn :)

Answer 32

yes please

Answer 33

ok :)

Answer 34

ok so -3(3x + y) = -3(79)
y = - 237

Answer 35

Distribute -3 in:
-3 ( x + 5y = 101)
-3x + .. = ....

Answer 36

oh to make them equal so we can subtract ( well not necessarily =)
so it is
3x + y = 79
-3x - 15y = -303

Answer 37

-14y = -224
------------
-14

Answer 38

=16
y = 16

Answer 39

so now can we substitute y in 3x + y = 79
to be 3x + 16 = 79

Answer 40

3x + 16 = 79
- 16 -16
3x= 63
---------
3
x = 21

Answer 41

thank you so much... but i have a second problem i need he;p with if you are willing

Answer 42

Typo x = 21 degree!

Answer 43

Not yet, the last step is replace x, y values into the angles:
-> 4y = 64 degree
....

Answer 44

oh no i wasnt solving for degrees just for the values of x and y

Answer 45

but will you help me with my next problem?

Answer 46

Oh, so it's done :)
To make it simple, open new post per question :)

Answer 47

ok i will h/o

Answer 48

Make sure you understand the concept prior to moving on the next level!