Answer:
Sample Response: No, Tony is not correct. Solving the inequality tells us that x is greater than or equal to 37.5. Since the class must wash a whole number of cars, they need to wash at least 38 cars.
Let x be the number of needed years.
1. He deposits $10,000 into his checking account and he will withdraw $1,200 from his checking account each year. Then after x years he will have $10,000-$1,200x in his checking account.
2. He deposits $2,000 into his savings account and his savings account earns 8% interest each year, then after x years he will have
3. Equate these amounts of money:
4. Solve this equation:
Conclusion: he needs nearly 6.663 years.
Answer:
HERE
Step-by-step explanation:
To determine which system has x = 3 and y = 2.5 as its solution, we need to substitute these values into each system of equations and check which one satisfies the conditions.
System 1: 7x - 5y = 33.5
Substituting x = 3 and y = 2.5:
7(3) - 5(2.5) = 21 - 12.5 = 8.5
System 2: 3x + 3y = 1.5
Substituting x = 3 and y = 2.5:
3(3) + 3(2.5) = 9 + 7.5 = 16.5
System 3: 4x + y = 9.5
Substituting x = 3 and y = 2.5:
4(3) + 2.5 = 12 + 2.5 = 14.5
System 4: 5x - y = 12.5
Substituting x = 3 and y = 2.5:
5(3) - 2.5 = 15 - 2.5 = 12.5
System 5: 2x - 5y = 18.5
Substituting x = 3 and y = 2.5:
2(3) - 5(2.5) = 6 - 12.5 = -6.5
System 6: x + y = 5.5
Substituting x = 3 and y = 2.5:
3 + 2.5 = 5.5
System 7: 11x + 10y = 8
Substituting x = 3 and y = 2.5:
11(3) + 10(2.5) = 33 + 25 = 58
System 8: 5x - 2y = -20
Substituting x = 3 and y = 2.5:
5(3) - 2(2.5) = 15 - 5 = 10
From the calculations, we can see that only System 4: 5x - y = 12.5 satisfies the given conditions when x = 3 and y = 2.5. Therefore, the correct answer is System 4.