Since both equations = y then they must be equal to each other.
x^2 - x-1 = 2 - 3x
To solve, you need all terms on one side and zero on the other.
x^2+2x -3=0
Factor
(x+3)(x-1) = 0
so x = -3 and x = 1
now to find y.. substitute -3 for x in each equation and then 1 for x in each equation.
This is different from straight lines which only cross in one place. You have a parabola and a straight line so they will cross in two places.
Simultaneous equations...
y = x^2 - x - 1
y = 2 - 3x
Many thanks.
3 answers
How did you get +2x would it not be -2x?
x^2 - x - 1 = 2 - 3x
Add x to each side...
x^2 - 1 = 2 - 2x
Then add 1 to each side and that makes the equation...
x^2 = 3 -2x
?????????
x^2 - x - 1 = 2 - 3x
Add x to each side...
x^2 - 1 = 2 - 2x
Then add 1 to each side and that makes the equation...
x^2 = 3 -2x
?????????
you can do it that way, but how has that helped?
How do you solve x^2 = 3-2x ?
How do you solve x^2 = 3-2x ?
2 answers