Answer:
n=5
Explanation:
Given that f(x) from x to y is linear. Hence equation would be that of a straight line. Given (-4,-25) and (-1,-10) are points on the line
Using two point formula we have
![(y+25)/(-10+25) =(x+4)/(-1+4)\\(y+25)/(15)=(x+4)/(3)\\y+25 =5x+20\\y=5x-5](https://img.qammunity.org/2019/formulas/mathematics/high-school/ehbh3pw7yihfxlzyfqag4ito2x1t58dwar.png)
Using this we can find n for f(x) = y =20
Substitute to get
![20=5n-5\\5n=25\\n=5](https://img.qammunity.org/2019/formulas/mathematics/high-school/qbtbm69ffj31yumkh7rkd02h1yuud8dong.png)