Answer:
x = -4; y = -3
Step-by-step explanation:
2x - 5y = 7
3x - y = -9
Rewrite top equation. Multiply both sides of bottom equation by -5. Add equations. This eliminates y, and we solve for x.
2x - 5y = 7
(+) -15x + 5y = 45
----------------------------
-13x = 52
Divide both sides by -13.
x = -4
Substitute -4 for x in the first original equation and solve for y.
2x - 5y = 7
2(-4) - 5y = 7
-8 - 5y = 7
-5y = 15
y = -3
Answer: x = -4; y = -3
-5 =
For A:
You add the probabilities to get the answer to A: = .75, or 3/4
Note that the probability of ALL THREE of them hitting would be 1/3 x 1/4 x 1/5.
For B:
2/3 and 3/4 is the probability of the other two people MISSING (the remainder of 1/3, 1/4)
1.0 = 100% chance to hit the target, so 1.0 x 2/3 x 3/4 = 1/2
Mark's chance of hitting is 1/5, so do 1/2 x 1/5, = 1/10
The triangle inequality requires the third side be in the range
.. 12 -4 ≤ third side ≤ 12 +4
.. 8 ≤ third side ≤ 16 . . . . . . . . . your answer is the number(s) in this range
_____
Some define the triangle inequality using < rather than ≤. Be careful here.
6(-3-4y)
-18-24y
(Multiply 6 by both numbers)
