Answer: 1. d.
2. a. (5, 28)
3. a: C(n) = 0.90 n - 0.40
Step-by-step explanation:
1. Here x represents the saving of one day.
Thus, the total saving for 7 day = 7 x
And, my goal is to save at least $350.00 ( According to the question)
⇒
⇒ ( by dividing both sides by 7 )
Therefore, Option d is correct.
2. since, if a point satisfies an equation then we can say that it is the solution of the equation.
(5,28) satisfies y= 5x + 3
Because at x = 5, 5×5 + 3 = 25 + 3 = 28
except this point other points (28, 5), (4, 20) and (3, 19) are not satisfying given equation of line.
Therefore, only (5,28) is the solution of line.
⇒ Option a is correct.
3. Here n represents the number of tunas.
And, according to question the cost of one tuna = $0.90
⇒ Cost of n tunas = $ 0.90n
But again according to the question,
I have a coupon for $0.40 off your total purchase.
Thus, $ 0.40 will be less from my total purchasing cost.
⇒ The cost of n tunas = $ (0.90 n - 0.4)
Option a is correct.