# Practice Problems 1 2 3 4 5 6 7 8 9 Return to MENU Practice Problems 123456789123456789.

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Practice Problems 1 2 3 4 5 6 7 8 9 Return to MENU Practice Problems 123456789123456789

Practice Problem #1 What is the sum of the solutions for y = x + 3 3x + y = 5 ANSWER

Answer 1) What is the sum of the solutions for y = x + 3 3x + y = 5 Return to Practice Problems

Practice Problem #2 Solve. Write your answer as an ordered pair. -0.5x + y = - 1 y - 1 = 2 -7x + 2 ANSWER

Answer 2) Step 1: solve each equation for y -0.5x + y = - 1 becomes y = 0.5x - 1 y - 1 = 2 -7x + 2 becomes y = -7x +5 Step 2: solve by substitution 0.5x – 1 = -7x + 5 7.5x = 6 x = 0.8 Step 3: use y - 1 = 2 -7x + 2, substitution 0.8 for x y – 1 = 2 – 7(0.8) + 2 y = 2 – 5.6 + 2 + 1 y = -0.6 Answer: (0.8, -0.6) Return to Practice Problems

Practice Problem #3 Solve the system. What is the sum of x and y? y = 9x + 20 y = -1/3 x + 13 ANSWER

Answer 3) y = 9x + 20 y = -1/3 x + 13 Use substitution 9x + 20 = -1/3x + 13 +1/3x 9 1/3x + 20 = 13 Return to Practice Problems 9 1/3x + 20 = 13 -20 -20 9 1/3x = -7 9 1/3 x = -3/4 y = 9(-3/4) + 20 y = 13.25 Sum is -0.75 + 13.25 Sum is 12.5

Practice Problem #4 Solve. What is the product of x and y? 2y = 3x + 4 y = -2x - 1.5 ANSWER

Answer 4) Solve. What is the product of x and y? 2y = 3x + 4 y = -2x - 1.5 Answer: -0.5 Return to Practice Problems

Practice Problem #5 Clair bought three bars of soap and five sponges for \$2.31. Steve bought five bars of soap and three sponges for \$3.05. Find the cost of each item. ANSWER

Answer 5) Let x = price per bar of soap, y = price per sponge 3x + 5y = 2.31 5x + 3y = 3.05 x = \$0.52 y = \$0.15 Return to Practice Problems

Practice Problem #6 Kendra owns a restaurant. She charges \$1.50 for 2 eggs and one piece of toast, and \$.90 for one egg and one piece of toast. Write and graph a system of equations to determine how much she charges for each egg and each piece of toast. Let x represent the number of eggs and y the number of pieces of toast. ANSWER

Answer 6) Let e = price per egg, t = price per slice of toast 2e + t = 1.50 e + t = 0.90 \$0.60 per egg \$0.30 for toast Return to Practice Problems

Practice Problem #7 Sharon has some one-dollar bills and some five-dollar bills. She has 14 bills. The value of the bills is \$30. Solve a system of equations using elimination to find how many of each kind of bill she has. ANSWER

Answer 7) Let x = 1 dollar bills, y = 5 dollar bills x + y = 14 x + 5y = 30 4 five-dollar bills 10 one-dollar bills Return to Practice Problems

Practice Problem #8 Tickets to a local movie were sold at \$6.00 for adults and \$4.50 for students. There were 240 tickets sold for a total of \$1,155.00. Find the number of adult tickets sold and the number of student tickets sold. ANSWER