I don't understand what I did wrong, please help​

Step-by-step explanation:

Lets start with the easiest part of this question - simply plugging in to get easier equations:

Something that now immedietly pops out is that many of the terms would cancel if we added them together. We get the following results by adding the two equations together:

Now lets look at the other bit of inromation the question gives you -- that the two points are horizontal tangents. Taking the derivative of the standard form of a cubic, we get:

Since the points are both horizontal tangents, y' will be equal to 0 at the points. Thus, plugging in we get:

We again see a simple subtracting opportunity that will cancel out two terms:

Now going back to the equation we got by adding the two equations that we got from simply plugging our points in:

Now that we have b and d, we can now plug them back into our step one and derivative equations in order to get a simple system:

Solving for a and c, we get:

Thus, finally, our answer is:

Attached is desmos, which you can use to check.

720

step-by-step explanation:

first i did work 2nd i did work and 3rd i did work

if x decreases by 4 then y increases by 10

step-by-step explanation: