1. solve for x in first to just find nterms of y
x=12-y
sub that for x in other one
first divide that one by 2 to make it easier
2x-y=18
2(12-y)-y=18
24-2y-y=18
24-3y=18
minus 24 both sides
-3y=-6
divide -3
y=2
D is answer
2.
find intersection of x+y=5 and -2x+3y=6
or easiers, just test the intersections
wait, they all intersect in the same place
this is super easy
pick ANY point that is in that reigon and see if it is true
A, if we pick lets say (5,5)
that is false for x+y<5
not A
B
pick (10,0)
false for first one
not B
C
pick (0,0)
true for first
false for 2nd
not C
D. pick (-10,0)
true for first
true for 2nd
answer is D
answer is D for both questions
Answer:
Step-by-step explanation:
Answer:
formula for a circle: (x-h)^2 + (y-k)^2 = r^2, where (h,k) is the center and r is the radius.
1. Plug in center coordinates into formula
(x-3)^2 + (y-(-6))^2 = r^2
2. Plug in radius value
(x-3)^2 + (y-(-6))^2 = 5^2
3. Simplify:
(x-3)^2 + (y+6)^2 = 25
Is the same as the one you just did.
keep in mind that, going against the current, the current's speed erodes speed from your regular speed, whilst if you're going with the current, the current's speed adds to it.
now, in this case, you row 5mph, going upstream you're only doing 3mph, whatever happened to the other 2mph? well, the current speed eroded them, meaning the speed of the river is 2mph.
now, going downstream with the current, your regular speed is 5mph, and the current is 2mph, since the current adds to yours, then you're going 5 + 2, mph.
