18 students scored 80%
22 students scored 70%
((18 × .8) + (22 × .7)) ÷ .4
(14.4 + 15.4) ÷ .4
(29.8) ÷ .4
74.5
The average score of the whole class was 74.5
Answer:
x=-14
Step-by-step explanation:
a. The equation that models the amount in the savings account in terms of the number of months is y = 8107 - 100 x
b. He will have $4507 after 36 months
Step-by-step explanation:
The form of the slope-intercept equation is y = m x + b, where
- m is the slope (constant rate)
- b is the intercept (initial amount value y at x = 0)
∵ The man decides to take out $100 per month from his
savings account
- That means the constant rate is 100 dollars per month, that money
will detected from his initial money every month
∴ m = 100
∴ The form of the equation is y = b - 100 x, where
- x represents the number of the months
- y represents the amount of money in his saving account in x months
To find the value of b substitute x and y by the given information
∵ He has $3507 in his account after 46 months
∴ x = 46 and y = 3507
∵ 3507 = b - 100(46)
∴ 3507 = b - 4600
- Add 4600 to both sides
∴ 8107 = b
∴ y = 8107 - 100 x
a. The equation that models the amount in the savings account in terms of the number of months is y = 8107 - 100 x
∵ y = 8107 - 100 x
∵ x = 36
∴ y = 8107 - 100(36)
∴ y = 8107 - 3600
∴ y = 4507
b. He will have $4507 after 36 months
Learn more:
You can learn more about the linear equations in brainly.com/question/9801816
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Answer:
2,320
Step-by-step explanation:
4.2% gets taken every year and there is 10 year,so 4.2% s uqual to 0.042,so just mutiply 4000 by 0.042 which is 168,then times 168 by 10 which brings you to 1680 and 4000 subtracyed by 1680,which equals 2,320