If z=9/2 is a solution of the equation 2z²+kz-30=6, find:
a) the value of k
b) the other solution of the equation
I appreciate any form of help, thank you
+33616 a) Substitute 9/2 for z in the equation:
2*(9/2)2 + k*9/2 - 30 = 6
81/2 + 9k/2 = 36
81 + 9k = 72
9k = -9
k = -1
b) Use this value of k in the original equation:
2z2 - z -30 = 6
2z2 - z -36 = 0
z2 - z/2 -18 = 0
(z + 4)(z - 9/2) = 0
The other solution is therefore z = -4
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