91Ó°ÊÓ

Find each of the products and express the answers in the standard form of a complex number. $$ (7 i)(-9+3 i) $$

Solve Problems 64-67 for the indicated variable. Assume that all letters represent positive numbers. $$ s=\frac{1}{2} g t^{2} \quad \text { for } t $$

For Problems \(63-68, a\) and \(b\) represent the lengths of the legs of a right triangle, and \(c\) represents the length of the hypotenuse. Express answers in simplest radical form. Find \(a\) if \(c=8\) feet and \(b=6\) feet.

Find each of the products and express the answers in the standard form of a complex number. $$ (-6 i)(-2-7 i) $$

Solve Problems 64-67 for the indicated variable. Assume that all letters represent positive numbers. $$ A=\pi r^{2} \quad \text { for } r $$

Set up an equation and solve each problem. Suppose that \(\$ 500\) is invested at a certain rate of interest compounded annually for 2 years. If the accumulated value at the end of 2 years is \(\$ 594.05\), find the rate of interest.

For Problems \(63-68, a\) and \(b\) represent the lengths of the legs of a right triangle, and \(c\) represents the length of the hypotenuse. Express answers in simplest radical form. Find \(b\) if \(c=17\) yards and \(a=15\) yards.

The solution set for \(x^{2}-4 x-37=0\) is \(\\{2 \pm \sqrt{41}\\}\). With a calculator, we found a rational approximation, to the nearest one-thousandth, for each of these solutions. $$ 2-\sqrt{41}=-4.403 \quad \text { and } \quad 2+\sqrt{41}=8.403 $$ Thus the solution set is \(\\{-4.403,8.403\\}\), with the answers rounded to the nearest one-thousandth. Solve each of the equations in Problems 64-73, expressing solutions to the nearest one-thousandth. $$ x^{2}+10 x-46=0 $$

For Problems \(63-68, a\) and \(b\) represent the lengths of the legs of a right triangle, and \(c\) represents the length of the hypotenuse. Express answers in simplest radical form. Find \(b\) if \(c=14\) meters and \(a=12\) meters.

Find each of the products and express the answers in the standard form of a complex number. $$ (-9 i)(-4-5 i) $$