Answer:
Step-by-step explanation:
Given is a function f in two variables as

To find critical points of the given function and also to find max, min or saddle point.
Find the partial derivatives



Equate first derivatives to 0
Adding fx and fy we get

x=±y
Only real roots are (x,y) =(3,3) and (-3,-3)

(3,3) is a saddle point

(-3,-3) is also a saddle point.
Do multiplication first than divide
first add an than subtract
2 lines parallel, and 2 triangles have a common angle
So the smaller Δ is similar to the bigger Δ (AA Similarity)
9:(4x-2)+9=12:(3x+2)+12
9:4x+7=12:3x+14
9(3x+14)=12(4x+7)
27x+126=48x+84
21x=42
x=2
So the answer is x=2
Let x be equal to Jim's travel time
Let x + 2 be equal to Joan's travel time
distance = speed*travel time
6(x + 2) + 8x = 33
6x + 12 + 8x = 33
14x = 21
x = 21/14 = 3.5
3.5 hrs is the hours that Jim have been running until he met Joan.
<span> -vp + 30 < 45 for v.
</span> -vp < 15
v > -15/p
hope it helps