Acubic polynomial function f has a leading coefficient 2 and a constant term 7 if f(1)=7 and f(2)=9 what is f(-2)?

So what we know with this function is that:

Using this info, we can create 2 different equations:

Now, simplify each of them:

Now with these 2 simplified equations, we can do a system of equations to solve for b and c of this cubic function. For this, I will be using the elimination method. Firstly, divide both sides of the second equation by 2:

Next, subtract the first equation from the second equation to get . We have found b.

Next, to find c plug in -5 into the b variable either equation and then solve for c:

Putting it together, our cubic function is

Now, to find f(-2), plug -2 into the x variable and solve:

In short, f(-2) = -35.

the equation for this situation is y=122+45. to solve the equation you would add 45 and 122 to get a total of 167lbs. in conclusion, grace's weight eight weeks ago was 167lbs.