Hello, this is my brother's homework. I'm a little bit confused since I studied this lesson a long time ago..Can someone help me? I am not sure about my answer..

Given the equation f(x)=a(b)x where the initial value is 40 and the growth rate is 20% what is f(4)

The diagram represents the polynomial 4x2 + 23x – 72. what is the factored form of 4x2 + 23x – 72? (4x + 8)(x – 9) (4x – 8)(x + 9) (4x + 9)(x – 8) (4x – 9)(x + 8)

10x − 5y + 14 = 0 whats the answer pls