Answer:
125 is the square of 25 I hope
Change the function into vertex form:
f(x)=x²-10x+16
make a square by (adding half of -10)², which is 25, then subtract it:
f(x)=x²-10x+25-25+16
f(x)=(x-5)²-9
so the vertex is at (5,-9)
another way to do it:
f(x)=x²-10x+16
the vertex is when x=-

, b=-10, a=1 in this case.
x=-(-10/2*1)=5
plug x=5 into the quadratic function, you get f(x)=-9
The answer is 21
First you po perenthies which would be 8-6=2 the equation now is 5+4×(2)2
Then you to exponents which would be 2×2=4 the equation now is 5+4×4
Now you multiply 4×4=16 the equation is now 5+16
Now you add 5 and 16 to get 21
6+5(9/3)2
6+5(3)2
6+5+6
11+6
17