Answer:
x=39, y=180
Step-by-step explanation:
f(x)=0.4x²-31.2x+788.4
For x=39 the graph reaches its lowest point.
The minimum value of y is:
x=39→y=f(39)=0.4(39)²-31.2(39)+788.4
y=f(39)=0.4(1,521)-1,216.8+788.4
y=f(39)=608.4-1,216.8+788.4
y=f(39)=180
