Can someone pls help me I’m stuck on this question

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).

The local farm is advertising a special on fresh picked peaches. the farm charges $4.25 to pick your own peck of peaches and $3.50 for each additional peck you pick. write an equation for the total cost of peaches in terms of the number of pecks. deine your variables. how much does it cost to pick 3 pecks of peaches?

Tim's phone service charges $26.39 plus an additional $0.21 for each text message sent per month. if tim's phone bill was $31.64, which equation could be used to find how many text messages, x, tim sent last month?