Question

...Solve the following system of equations and show all work.

y = 2x2
y = –3x −1

Answer 1

@radar

Answer 2

please help... I Dont understand

Answer 3

since both expressions in x are equal to y then they are equal to each other so
2x^2 = -3x - 1

Answer 4

this is a quadratic so write it as
2x^2 + 3x + 1 = 0

can you solve this for x?

Answer 5

what do i do with the 2x^2

Answer 6

this will factor to the form
(2x + a)(x + b) = 0

to find a and b you need to find 2 numbers a and b where ab = 1 and a + 2b = 3

Answer 7

okay hold on while i figure this sorry im really bad at this

Answer 8

i cant im coming up with things like 2x+ 3x+ 2

Answer 9

and thats not right

Answer 10

what 2 numbers multiplied together give + 1?
- think of the obvious ones

Answer 11

-1 and -1
1 and 1

Answer 12

yes either of those but also
a + 2b = 3

so which ones are they?

Answer 13

plug in the -1 and -1 and then the 1 and 1 and see which of these fit

Answer 14

for the negatives i got -3

Answer 15

and the positive i got 2

Answer 16

2 for the positive? try again

Answer 17

you need it to be = 3

Answer 18

yes now ive got it lol i must of did it wrong

Answer 19

now that we have that info what do i do next

Answer 20

you now have the values of a and b so we can factor the equation
(2x + 1)(x + 1) = 0
now when 2 things are multiplied and the result is 0 then either one of these can be 0
so we have
2x + 1 = 0 or x + 1 = 0

so you can solve these 2 equations to give 2 values of x

then using these values of x plug them into one of the original equations to give the corresponding values of y

Answer 21

okay thank you .