Practice Exercises
In Exercises 1–18, solve each system by the substitution method.
18.
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EBK COLLEGE ALGEBRA ESSENTIALS
- For Exercises 15–22, solve the system by using the addition method. (See Examples 3-4) 15. 2x + 3y = 11 16. 3x + y² = 21 17. x - xy = 20 18. 4xy + 3y² = -9 2 + 4y = 8 4x - 2y = -2 -2x2 + 3xy = -44 2xy + y = -5 21. x = 1- y 9x - 4y? = 36 19. 5x - 2y2 = 1 20. 6x + 5y = 38 7x - 3y = 9 22. 4x = 4 - y? 16y = 144 + 9x? 2x - 3y = -4arrow_forwardAn important application of systems of equations arises in connection with supply and demand. As the price of a product increases, the demand for that product decreases. However, at higher prices, suppliers are willing to produce greater quantities of the product. Exercises 97–98 involve supply and demand. 97. A chain of electronics stores sells hand-held color televisions. The weekly demand and supply models are given as follows: Number sold Demand model per week N = -5p + 750 Price of television Number supplied to the chain per week N = 2.5p. 1apow hjddns a. How many hand-held color televisions can be sold and supplied at $120 per television? b. Find the price at which supply and demand are equal. At this price, how many televisions can be supplied and sold each week?arrow_forwardIn Exercises 3–6, solve each system by graphing. Identify systems with no solution and systems with infinitely many solutions, using set notation to express their solution sets. 3. x + y = 5 3x - y = 3 4. [3x – 2y = 6 16x – 4y = 12 3 y 6. [y = -x + 4 |3x + 3y = -6 5. 5h 2х — у %3D — 4arrow_forward
- In Exercises 15–16, solve each system by eliminating variables using the addition method. 15. [3x + 12y = 25 |2r - 6y = 12 x + 3y -x + 2y + 3z 2х - 5у — г 16. 5 13 -8arrow_forwardsolve th e given system 2x + y = -1 , 5x + 3y = 2arrow_forward1–18, use the elimination-by-addition method to solve each system. (3x - 2y=5) (2x + 5y=-3)arrow_forward
- Exercises 59–66: Use the intersection-of-graphs method to solve the equation. Then solve symbolically. 63. -х + 4 %3D 3хarrow_forwardSection 3: Solve each system by elimin ( 2x + y = 25 1. (3y = 2x – 13 75y=2X+Yarrow_forwardPART 4 17. Solve the following system by the ELIMINATION METHOD (by hand) show work. 3x + 4y = 26 5x – 5y = 20arrow_forward
- 5- What value of b will cause the system to have an infinite number of solutions? y = 6x - b -3x + y= -3 Save and Exit Nmt Submit 2. 4.arrow_forward1–18, use the elimination-by-addition method to solve each system. (x - 2y=-12) (2x + 9y=2) Kaufmann, Jerome E.; Schwitters, Karen L.. Intermediate Algebra (p. 521). Cengage Learning. Kindle Edition.arrow_forwardThe owl population in a year n can be divided into juveniles, subadults andadults. Adults produce, on average, 0.4 juveniles each year. Approximately53% of juveniles survive to be subadults the next year, while 73% of subadultssurvive to become adults. Approximately 89% of the adult population survivesfrom one year to the next.1. Write down the equations for juveniles, subadults and adults in the year n+1 as functions of the juvenile,subadult and adult populations at year n. Explain all terms.2. Carefully explaining your notation and the terms, write down a matrix equation of the form pn+1 = Apn. 3. If there are 21 juveniles, 17 subadults and 53 adults this year, how many of each would we expect nextyear? 4. What is the equation that would describe the population in 5 years? (Do not calculate it!)arrow_forward
- Algebra & Trigonometry with Analytic GeometryAlgebraISBN:9781133382119Author:SwokowskiPublisher:Cengage