simplify these expressions as fractions:

(26/27) + (35/4)

(26/27) x (35/4)

(3x/2y^2) x (2yx/x^2) and what are the restrictions of x, y?

(3x^y/zw) + (tx^2y^3w^4/z) and what are the restrictions for he variables x, y, z, t, w to make the expression well defined?

i'm not sure how to go about solving these, could someone please help?

(26/27) + (35/4)

(26/27) x (35/4)

You need a common denominator to add fractions. Whe multiplying them, you can try canceling common factors first. For example
26/27 + 35/4 = (104 + 945)/108
= 1049/108 = 9 77/108

26/27 x 35/4 = ?
Note that the 26 and the 4 are both divisible by 2, and cancel out that factor from the numerator and denominator, giving
13/27 x 35/2 = 455/54
= 8 23/54

In you last question, you seem to have omitted the exponent of x in the first term's numerator. Do the problems the same way as I showed you, using common denominators for addition and cancelling common algebraic factors for the multiplication