Hello could someone please help me answer and explain these?

5. What kind of preferences are represented by a utility function of the form u($1, X2) = X1+Vx2? Is the utility function v(X1, X2) = x1 + 221\\*2+ 2 a monotonic transformation of u(X1, 2)? 6. Consider the utility function u(21, X2) = Vx142. What kind of pref- erences does it represent? Is the function v(1, 72) = 2172 a monotonic transformation of u(X1, X2)? Is the function w($1, X2) = x1x5 a monotonic transformation of u(x1, 2)? 7. Can you explain why taking a monotonic transformation of a utility function doesn't change the marginal rate of substitution