Your answer would be 0.315 because:P(2\ spades)=\frac{13C2\times 39C4}{52C6}=0.315
n, n+1 - two consecutive integers
n(n + 1) = 50 <em>use distributive property</em>
n² + n = 50 <em>subtract 50 from both sides</em>
n² + n - 50 = 0
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ax² + bx + c =0
if b² - 4ac > 0 then we have two solutions:
[-b - √(b² - 4ac)]/2a and [-b - √(b² + 4ac)]/2a
if b² - 4ac = 0 then we have one solution -b/2a
if b² - 4ac < 0 then no real solution
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n² + n - 50 = 0
a = 1, b = 1, c = -50
b² - 4ac = 1² - 4(1)(-50) = 1 + 200 = 201 > 0 → two solutions
√(b² - 4ac) = √(201) - it's the irrational number
Answer: There are no two consecutive integers whose product is 50.
36 -81.9 - 45.9 I keep getting -45.9
So you know that:
2x+y=14+y
and
5x-y=x+13y
Here you have two equations with two unknown variables:
If you isolate x from the second equations you get:
x=(7/2)y
Insert that in the first equations and solve for y:
2*(7/2)y+y=14+y
y=2
Insert that value for y in one of the two equations (i chose the first):
2x+2=14+2
x=7
Therefore x=7
Hope that helped.
Actually you could start with isolating x, and then insert that in one of the two equations.
