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:
Cube
X =8.25
Step-by-step explanation:
Answer:
8
Step-by-step explanation:
0) the basic formula is: L=v*t, where L - distance, v - speed/velocity; t - time;
1) if the person's speed in still water is 'v' and the speed of water is 5 (according to the condition), then the upstream speed is 'v-5' and the downstream speed is 'v+5';
2) according to the condition the upstream time and the downstream time are the same, it means t₁=t₂=t, where t₁=upstream time and t₂=downstream time;
3) according to the items above it is possible to make up the equation of the upstream travel: t(v-5)=3; ⇒ t=3/(v-5);
4) according to the items above it is possible to make up the equation of the downstream travel: t(v+5)=13; ⇒ t=13/(v+5);
5) if t=3/(v-5) and t=13/(v+5), then

11 is 110 for x and y
12 is 90 degrees for x and y
13 is also 90 degrees for x and y