Question

Solve the systems of non linear equations.. Can you please help me walk through this, for some reason I cant seem to get how to do it still..

2x^2-18x-y=-21
-4x^2+3x-y=-6

Answer 1

for doing this sum u need to eliminate,y and then proceed to solve the quadratic equation. now corresponding to values of x u'll get value(s) for y.
clue:subtract both the equations to eliminate y.

Answer 2

Subtract them together?? What do you mean like use the substitution method??

Answer 3

he is referring to the elimination or addition method where you try to eliminate a variable by adding the equations (adding the coefficients)

Answer 4

you could also use substitution, solve each equation for y then set them equal to each other

Answer 5

think you get it now?

Answer 6

no

Answer 7

I dont see how I change the soultion to y='s i need to get points for my answer (x,y) and there may be more than one set of points

Answer 8

I did the substitution method and got:
-2x^2+15x=-27

Answer 9

ok not quite
y=2x^2 -18x +21
y=-4x^2 +3x +6
2x^2 -18x +21 = -4x^2 +3x+6
6x^2 -21x +15 = 0

Answer 10

then factor
3(2x^2 - 7x +5) =0
3(2x-5)(x-1) = 0
x=1
x=5/2

y = 2(1)^2 -18(1) +21 = 5
y=2(5/2)^2 -18(5/2) +21 = -23/2

Answer 11

ok sorry been trying to work this out

Answer 12

dumbcow: can u please think about my question? the sphere and light source question ?