Phone Charges The monthly cost C, in dollars, for calls from the United States to Japan on a certain phone plan is
modeled by the function C(x) = 0.24x + 5, where x is the
number of minutes used.
(a) What is the cost if you talk on the phone for x = 50
minutes?

Find the gradient of f(x, y,z)equals=left parenthesis x squared plus y squared plus z squared right parenthesis superscript negative 1 divided by 2 baseline plus ln left parenthesis x right parenthesis x2+y2+z2−1/2+ln(xyz) at the point left parenthesis negative 2 comma 1 comma negative 2 right parenthesis(−2,1,−2).

How to solve a simultaneous equation involved with fractions?

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