ANSWER
-9
EXPLANATION
We want to evaluate the line integral:
[tex]\int_{(2,1,2)}^{(6,7,-5)}ydx+xdy+7dz[/tex]
The parametric equations for the line segment from (2,1,2) to (6,7,-5) is
[tex]x = 2 + 4t[/tex]
[tex]y= 1 + 6t[/tex]
[tex]z= 2 - 7t[/tex]
This implies that:
[tex]dx = 4dt[/tex]
[tex]dy = 6dt[/tex]
[tex]dz = - 7dt[/tex]
Our integral now becomes:
[tex]\int_{0}^{1} (1 + 6t)(4)+(2 + 4t)(6) + 7( - 7)dt[/tex]
We simplify to get:
[tex]\int_{0}^{1} 48t - 33dt[/tex]
This integral evaluates to:
[tex]\int_{0}^{1} 48t - 33dt = - 9[/tex]