Answer:
Step-by-step explanation:
Step 1, coefficience of X= -8
Step 2, divide coefficience by 2 =-4
Step 3, Square the answer= 16
step 4, Add to both sides of the equation
s^2-8x+16=4+16
s^2+16=20
s^2+4^2=20
(s+4)^2=20
take the squre root of both sides
s+4=sqrt(20)
s=4+or -sqrt20
s=4+4.5 or 4-4.5
s=8.5 or 0.5
rounding up we have
s=10 or 1(to the nearest ten0)