Given that f(x)=x^2-1 and g(x)=x-4, the value of (f*g)(10) will be:
f*g=(x^2-1)(x-4)
=x^2(x-1)-1(x-4)
=x^3-x^2-x+4
=x^3-x^2-x+4
next we find (f*g)(10), we substitute the value of x in our expression.
(f*g)(10)=10^3-10^2-10+4
=894
The answer is H1 and H2 on top then T1 and T2 on the bottom.
OK first let's check the x=1.5.





Oh my, that's called a depressed cubic, no

term. There's a formula for these very much like the quadratic formula but you're probably not quite old enough for that. Anyway,

is a solution, but that's not what they're asking. They are asking us to compare

with

and conclude

It turns out we did need all the rest of it. Save those brain cells, there's lots more math coming.
~~~~~~~~~~~~~~
I love it when the student asks for more. Here's the formula for a depressed cubic. I won't derive it here (though I did earlier today, coincidentally, but I'm probably not allowed to link to my Quora answer "what led to the discovery of complex numbers" from here). We use the trick of putting coefficients on the coefficients to avoid fractions.

has solutions
![x = \sqrt[3] { q - \sqrt{p^3 + q^2} } + \sqrt[3] {q + \sqrt{p^3 + q^2} } ](https://tex.z-dn.net/?f=x%20%3D%20%5Csqrt%5B3%5D%20%7B%20q%20-%20%5Csqrt%7Bp%5E3%20%2B%20q%5E2%7D%20%7D%20%2B%20%5Csqrt%5B3%5D%20%7Bq%20%2B%20%5Csqrt%7Bp%5E3%20%2B%20q%5E2%7D%20%7D%20%0A%0A)
That's pretty simple, though sometimes we end up having to take the cube roots of complex numbers, which isn't that helpful. Let's try it out on

That's
so
![x = \sqrt[3] { 3 - \sqrt{(2/3)^3+9} } + \sqrt[3] {3 + \sqrt{(2/3)^3+9} }](https://tex.z-dn.net/?f=x%20%3D%20%5Csqrt%5B3%5D%20%7B%203%20-%20%5Csqrt%7B%282%2F3%29%5E3%2B9%7D%20%7D%20%2B%20%5Csqrt%5B3%5D%20%7B3%20%2B%20%5Csqrt%7B%282%2F3%29%5E3%2B9%7D%20%7D%20)
![x = \sqrt[3] { 3 - \sqrt{753}/9 } +\sqrt[3]{3 + \sqrt{753}/9 }](https://tex.z-dn.net/?f=x%20%3D%20%5Csqrt%5B3%5D%20%7B%203%20-%20%5Csqrt%7B753%7D%2F9%20%7D%20%2B%5Csqrt%5B3%5D%7B3%20%2B%20%5Csqrt%7B753%7D%2F9%20%7D)

100% - 30% = 70%
The jacket will cost 70% of the original price.
Convert 70% into a decimal: 0.70
$44.00 × 0.70 = $30.80
The final price of the jacket is $30.80