I am practicing for my exams need help to see if i'm doing the right thing. Thank you

Determine the values of x in the following exponential equations:

(a)3x×27x + 81 = 729

(b)(23x)x + 32 = 1/256

5. Solve the following equations:

(e) y = 2x (f) 2x – y + 2 = 0

y = x2 + 1 4x + y – 5 = 0

(g) x – y = 0

5x – 3y = 10