Evaluate : `x times x times x times x`

Evaluate : x times x times x times y times y times y times y

Evaluate : x times x times x times y times y times y times y times z times z

Evaluate : x times x^2 times x^3 times x^4

Evaluate : x times x^2 times x^3 times x^4

Evaluate : x times x times y times y times y times y times z times z times z

Evaluate : x^a times x^b times x^c times x^(-d )

Evaluate : x^3 times x^5 times x^8 times x^7

Evaluate : y times y times y times y times x

Evaluate : x^7 times x^6 times x^(-2 ) times x^(-1 ) times x^5 =

Evaluate : ( c )   x times x times x times x times a times a times b times b times b ( d ) ( -2 ) times ( -2 ) times ( -2 ) times ( -2 ) times a times a times a