The probability the first marble will be blue is 28/40
The probability the second marble will be red is 12/39
The reason is because 28 + 12 = 40, so this makes the denominator for our first outcome, but then a marble is removed making our denominator 39 because 40-1 = 39.
If two pairs of corresponding angles in a pair of triangles are congruent, then the triangles are similar. We know this because if two angle pairs are the same, then the third pair must also be equal. When the three angle pairs are all equal, the three pairs of sides must also be in proportion.
hope this helps :)
X^2 + 16x + ?
a^2 + 2ab + b
(a + b)^2 which is a perfect square.
To find b to determine the last value, you divide 16x by 2x.
so:
b = 8
the last value would be 8^2 which is 64.
Hence answer is C - 64