Step-by-step explanation:

X^2 - 18x + 81 = 0
x^2 - 9x - 9x + 81 = 0
x(x - 9) - 9(x - 9) = 0
(x - 9)(x - 9) = 0
(x - 9)^2 = 0
x - 9 = 0
x = 9
Answer:-2/7
Step-by-step explanation:
m=y2-y1/x2-x1
m=slope
Its 5 marbles because if she pulls twice as many red than blue, it means you divide in half so you get 5
Hope this helped :D