Question

y = −x^2 + 4 y = 2x + 1
How would you solve by elimination or substitution?

Answer 1

we have : \[\rm y=-x^2+4~ and ~y=2x+1\]

Answer 2

yes, I don't get how you would solve them though

Answer 3

so we have two values for y

Answer 4

we can put any of those

Answer 5

like \[-x^2+4=2x+1\]

Answer 6

yes

Answer 7

now solve further :)

Answer 8

but how would you subract them. Thats what im stuck on.

Answer 9

here it is :
\[\rm 2x+1+x^2-4\]

Answer 10

that is what y equals then right?

Answer 11

no
since when we solve the equation we are left only with x.
then we will put the value of x in any one of the original equation to find the value of y

Answer 12

Im really stuck then .. how would you find what x and y are?

Answer 13

here it is :
\[\sf x^2+2x-3=0\]

Answer 14

we have to solve the quadratic equation

Answer 15

I get x = 1, -3

Answer 16

yep
now put one value at a time in either : y = 2x+1
or
y=-x^2+4

Answer 17

Thank you :)

Answer 18

Thank you
All the best :)