Trains Two trains, Train A and Train B, weigh a total of 204 tons. Train A is heavier than Train B. The difference of their weights is 104 tons. What is the weight of each train?
Train A weighs tons.

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 function show two sisters' savings account and the rate at which they plan to deposit money

What are two numbers that have a sum of 15?