5. \( (32-40+6) \cdot[-3+2 \cdot(-4-9-1+7):(12+16-29)] \)

What does the exponent in an expression indicate?

\( \left. \begin{array} { l } { ( x + y ) ^ { 3 } = z } \\ { ( y + z ) ^ { 3 } = x } \\ { ( z + x ) ^ { 3 } = y } \end{array} \right. \)

2. (B-2) \( \sqrt{\sqrt[3]{x}}=x^{a} \) bo'lsa, \( a \) ning qiymatini toping. \( \begin{array}{llll}\text { A) } a=\frac{2}{3} & \text { B) } a=\frac{1}{5} & \text { C) } a=\frac{5}{6} & \text { D) } a=\frac{1}{6}\end{array} \)

Three quantities \( t, x \) and \( y \) are such that \( t \) varies directly as \( x \) and invisely as the square root of \( y \). Find the percentage decrease in \( t \) if \( x \) decreases by \( 44 \% \).

\( \left. \begin{array} { l } { x ^ { 2 } - y ^ { 2 } + y } \\ { = 3 x ^ { 2 } y - y ^ { 3 } + x y } \end{array} \right. \)