Chapter 8: Problem 9
Find the inverse of each matrix. $$\left[\begin{array}{ll}-1 & 3 \\\\-1 & 4\end{array}\right]$$
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These are the key concepts you need to understand to accurately answer the question.
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Chapter 8: Problem 9
Find the inverse of each matrix. $$\left[\begin{array}{ll}-1 & 3 \\\\-1 & 4\end{array}\right]$$
These are the key concepts you need to understand to accurately answer the question.
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Apply elementary row operations to a matrix to solve the system of equations. If there is no solution, state that the system is inconsistent. \(\left\\{\begin{array}{rr}z+2 y= & 0 \\ z-5 x= & -1 \\ 3 x+2 y= & 3\end{array}\right.\) (Hint: Be careful with the order of the variables.)
At a certain gas station, the prices of regular and high-octane gasoline are \(\$ 2.40\) per gallon and \(\$ 2.65\) per gallon, respectively. Use matrix scalar multiplication to compute the cost of 12 gallons of each type of fuel.
This set of exercises will draw on the ideas presented in this section and your general math background. Find the inverse of $$\left[\begin{array}{lll}a & a & a \\\0 & 1 & 0 \\\0 & 0 & 1\end{array}\right]$$ where \(a\) is nonzero. Evaluate this inverse for the case in which \(a=1\)
A couple has \(\$ 10,000\) to invest for their child's wedding. Their accountant recommends placing at least \(\$ 6000\) in a high-yield investment and no more than \(\$ 4000\) in a low-yield investment. (a) Use \(x\) to denote the amount of money placed into the high-yield investment. Use \(y\) to denote the amount of money placed into the low-yield investment. Write a system of linear inequalities that describes the possible amounts the couple could invest in each type of venture. (b) Graph the region that represents all possible amounts the couple could put into each investment if they wish to follow the accountant's advice.
Consider the following system of equations. $$\left\\{\begin{aligned} x^{2}+y^{2} &=r^{2} \\ (x-h)^{2}+y^{2} &=r^{2} \end{aligned}\right.$$ Let \(r\) be a (fixed) positive number. For what value(s) of \(h\) does this system have (a) exactly one real solution? (b) exactly two real solutions? (c) infinitely many real solutions? (d) no real solution? (Hint: Visualize the graphs of the two equations.)
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