\( A^{-1}=\frac{1}{\operatorname{det} A}(\operatorname{adj} A) \)

What does the exponent in an expression indicate?

3) Sofia drove her Car 45 kelometers and sheran out of gos and had to waik 2 kelometers to a gass station. tter spead af drivingts 15 times here speed of walking. If the total time for the drive and walk was \( 1 / 2 \) hours, What was sofia's driving speed?

Solve the equation above for x . Which of the following is the correct answer? -3 \( 3 / 4 / 4 \) 7

81 If the equation \( x^{2}-6 x+9=\mathrm{b} \) has two real distinct roots, then \( \mathrm{b} \in \ldots \ldots . . . \). . \( \begin{array}{llll}\text { (a) } R & \text { (b) }]-\infty, 0] & \text { (c) }]-\infty, 0[ & \text { (d) }] 0, \infty[ \end{array} \)

If \( x \) represents the width of a rectangle and the length is four less than three times the width, which of the following expressions represents the length of the rectangle in terms of \( x \) ? \( 3 x-4 \) \( 4-3 x \) \( 4 x-3 \)