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.
so I don't know but just use the internet
A^2 + B^2 = C^2
7^2 + B^2 = 25^2
49 + B^2 = 625
-49 -49
B^2 = 576
Square root both sides
B = 24
She can get 21 portions. Since 2/3 and 42/3 already share the same denominator, all you need to do is divide 42 by 2 to get 21.
I can not see your choices but I'm assuming that this equation is what you are looking for: 16t+vt+ho. The other equation 4.9t+vt+ho is used for meters. I apologize if those weren't your choices as once again I can not see them.