Answer:
19/20 that's simplified by the way... and if you want the decimal form it's 0.95
For the first one c-9=(2)(4)+6
You are gonna multiply 2 and 4 first, 2*4=8. Now you have c-9=8+6. 8+6=14. So now the equation is c-9=14. Now we are going to add 9 to both sides. So c=23
For the second equation 10+y=90. We are going to subtract 10 from both sides. So, y=80.
Third, add 4 to both sides. a=10.
Fourth, subtract 8 from both sides. d=-9
Fifth, 5+2(3+4)=-x.
First we are going to add 3 and 4. 3+4=7. 5+2(7)=-x. Next we are going to multiply 2 and 7. 2*7=14. 5+14=-x. 5+14=19. So our equation is 19=-x. Next we are going to multiply both sides by -1. Making our final equation x=-19.
c=23
y=80
a=10
d=-9
x=-19
I hope that helps, if you need any further explanation just ask.<span />
Direct computation:
Parameterize the top part of the circle
by

with
, and the line segment by

with
. Then



Using the fundamental theorem of calculus:
The integral can be written as

If there happens to be a scalar function
such that
, then
is conservative and the integral is path-independent, so we only need to worry about the value of
at the path's endpoints.
This requires


So we have

which means
is indeed conservative. By the fundamental theorem, we have

2x/7 = 12/14
Multiply both sides of the equation by 7:
2x = 84/14
Simplify:
2x = 6
Divide both sides by 2 and your answer is....
x = 3