Question

Use substitution method to find the solutions for the simultaneous equation. Write your answer in a coordinate pair.

x+y=9
x^2-3xy+2y^2=0

Answer 1

Answer:x + y = 9 => y = 9-x

x^2 - 3xy + 2y^2 = 0

(x - y)(x - 2y)=0

x - y = 0 or x - 2y = 0

[This is a degenerate conic; i.e., two lines.]

For x-y=0:

x + y = 9

x - y = 0

2x = 9

x = 4.5

y = 4.5 b/c y = x

For x-2y=0:

2x + 2y = 18

x - 2y = 0

3x = 18

x = 6

y = 9 - x = 3

Solutions are: (4.5,4.5) and (6,3)

check:

x + y = 9?         √               √

x^2 - 3xy    4.5^2(1-3+2)

+ 2y^2 = 0?      √        36-54+18 √

Step-by-step explanation: