Answer:
<h3><em>
D. 880 = 45d + 70; 18 days.</em></h3>
Step-by-step explanation:
We are given fixed monthly charge = $70.
The cost of preschool per day = $45.
Number of days = d.
Total cost of d days = cost per day × number of days + fixed monthly charge.
Therefore, we get equation
880 = 45×d+70
<h3>880 = 45d +70.</h3>
Now, we need to solve the equation for d.
Subtracting 70 from both sides, we get
880-70 = 45d +70-70
810=45d
Dividing both sides by 45, we get

18=d.
Therefore,<em> 18 days Barry attended preschool last month.</em>
<em>Therefore, correct option is D option.</em>
<h3><em>
D. 880 = 45d + 70; 18 days.</em></h3>
40 x 5280 = 211200 feet per hour
211200 / 3600 = 58.666 = 59 feet per second
C is the rigth answer because all the other three has two x values in common. :)
The answer is B, the answer is 9,318,000= 9.318•10 to the 6th power
The coffee shop used 52 pounds of Type A coffee.
Step-by-step explanation:
Cost of Type A coffee per pound = 5.25
Cost of Type B coffee per pound = 4.10
Total pounds used in blend = 142
Total cost = 642.00
Let,
x be the pounds of Type A coffee used
y be the pounds of Type B coffee used
According to given statement;
x+y=142 Eqn 1
5.25x+4.10y=642.00 Eqn 2
Multiplying Eqn 1 by 4.10

Subtracting Eqn 3 from Eqn 2

Dividing both sides by 1.15

The coffee shop used 52 pounds of Type A coffee.
Keywords: linear equation, elimination method
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