So basically you want to isolate only one of the variable on one side so
y=-9+x^2
add 9 to both sides
y+9=x^2
square root both sides

x=
Depending on how many paintings there were you would divide that number by 129 to figure out how long it took to complete one painting. Hope this helps.
1.7*(x2+9)0.5+(10-x)=min
Also, the 2 is an exponent.
Given

on the interval 0 ≤ x ≤ 7, for maximum value, f'(x) = 0.
Answer:
(-2 , 2)
Step-by-step explanation:
A(-8 , 2) = (x1 , y1)
B(4 , -2) = (x2 , y2)
midpoint = (x1 + x2/2 , y1 + y2/2)
=(-8 + 4/2 , 2-(-2)/2)
=(-4/2 , 2+2/2)
(-2 , 2)
(3 , 7) = (x1 , y1)
(9 , 2) = (x2 , y2)
distance of PQ = 
=
=
=
=
=7.8 unit