Question

Solving a equation with two variables on each side 2x-3y=y-4x while 2x-3y = 42 & y-4x = 42, please explain how to do this

Answer 1

so you are given a system of 2 equations

i would recommend using substitution here
y-4x = 42 -----> y = 4x+42

2x - 3(4x+42) = 42

Answer 2

@dumbcow okay, I did this, the reason they both equal 42 us because they are congruent angles making an angle of 84, when I substituted, i got an answer of x = 8.4 and when you plug this back in to one of the two equations it doesn't give an answer that matched both

Answer 3

oh this is a geometry question, can you post the original diagram?

im getting x = -16.8

Answer 4

okay @dumbow <ABC, is split into two congruent angles <ABD and <DBC, line D bisecting < ABC. now, both angles are congruent and <ABC is 84, therefore both angles = 42? correct? angle <ABD = (2x-3y) and angle <DBC = (y - 4x) solve for x and y.

Answer 5

ok your equations are correct, as is the answer i gave above

Answer 6

@dumbcow

Answer 7

okay sorry @dumbcow my keyboard died, would you mind showing your work to get x = -16.8? im not getting that

Answer 8

@dumbcow nevermind I found it

Answer 9

haha im sorry, OS is not notifying me

Answer 10

@dumbow wait the next problem is hard to set up let me draw it for you

Answer 11

ok i better keep this post open

Answer 12

@dumbcow this is the exact problem, but I need help understanding how and where to find the information to use to solve each one, clearly I can just find X and Y and plug them in but what equation do i use and why?

Answer 13

oops let me redraw it it didnt work

Answer 14

@dumbcow

Answer 15

ok use angle addition
since AFE = 142 , and that represents all the angles added together

---> 13x +13y -4 = 142

BFD = BFC + CFD

---> 7x +5y -2 = 65

Now you have 2 equations to find x,y

Answer 16

so should I use substitution for this aswell? because it would turn into all fractions
P.S. the second problem would be y+15+39-x = 90 and x + 2y + 15 = 180?

Answer 17

darnit my drawing failed again

Answer 18

your choice, yes substitution wil give you fractions

if you dont want fractions, use elimination