X + k y = 1
k x + y = 1 / * ( - k )
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x + k y = 1
- k² x - k y = - k
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x - k² x = 1 - k
x ( 1 - k² ) = 1 - k
x = ( 1 - k ) / ( 1 - k² ) = ( 1 - k ) / ( 1 - k ) ( 1 + k )
y = 1 - k( 1 - k )/( 1 - k² )
y = ( 1 - k ) / ( 1 - k² ) = ( 1 - k ) / ( 1 - k ) ( 1 + k )
a ) For k = - 1 this system has no solution.
b ) For k ≠ - 1 and k ≠ 1, the system has unique solution:
( x , y ) = ( 1/ (1 + k) , 1/( 1 + k ) ).
c ) For k = 1, there are infinitely many solutions.
<h3>
Answer: 4/13</h3>
Explanation:
There are 13 hearts, including the queen of hearts. Then there are 3 more queens to get us to 13+3 = 16 cards we're after.
There are 16 cards we want out of 52 total, so the probability is 16/52 = (4*4)/(4*13) = 4/13
Answer:
x < -20
Step-by-step explanation:
x / -4 + 14 >20
Subtract 14 from each side
x / -4 +14-14 > 20 -14
x / -4 > 6
Multiply each side by -4, remembering to flip the inequality
x / -4 * -4 < 6 * -4
x < -20
Step-by-step explanation:
x² + 3x + 2
x² + x + 2x + 2 because 1+2=3 and 2×1=2
By taking out common terms, we get
x(x+1)+2(x+1)
(x+1)(x+2)
