-5y^2 + 2y + 2 = 0
y = -2 ± ✓4 - 4*-5*2. /. -10
y = -2 ± ✓44. / -10
y = -1 ± ✓11. / -5
(-1+✓11)/-5. and (-1-✓11)/-5
The slope can sometimes be called the gradient, and the equation for the gradient is (y2 - y1)/(x2 - x1). So therefore, you'd do: (-8 - 7)/(4 - -5) which is (-15)/9) which is -1 2/3 or -1.6 (recurring), which is your answer. I hope this helps! Let me know if I've confused you :)
Answer:
total marbles;12
after drawing red total counts are 7 red and 4 white 11 in total
probabilities are 4/11
12+8+8=28
8 students are wearing a blue shirt so the probability is 8/28
