9x - 2y = 11 ... (i)
5x - 2y = 15 ... (ii)
Subtracting equation (ii) from (i) we get;
4x + 0 = -4
4x=-4 , x = -1
Replacing x = -1 in equation (i) we get;
9(-1) - 2y = 11
-9 - 2y = 11
-2y = 20
y = 20 ÷ -2 = -10
The solution to the system of equations is (-1,-10).
Answer: x=r^2
+
10
r
+
25
There are a total of 8 balls
The probability of drawing a white ball is 4/8 on the first draw.
If you replace the ball then the probability will still be 4/8 for a white ball, since these events are independent of each other you multiply 4/8 x 4/8 = 16/64 or 1/4 then the probability of drawing at least 1 red ball with replacement is 1 - 1/4 = 3/4
Now without replacement:
the probability of drawing a white ball is 4/8 since you don't replace the ball then the probability of drawing a white ball the second time is 3/7 again multiply these two probabilities: 4/8 x 3/7 = 12/56 the the probability of drawing at least 1 red ball is 1- 12/56 = 44/56 or 11/14
C) 3/5 because they tossed the coin 5 times and out of those 5 times, 3 of them landed with different sides