1.y=-2x-3
2.y=2x+1
3.y=-3x-3
4.y=1/2x+2
Answers:
24 quarters
22 nickels
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Work Shown:
q = number of quarters
n = number of nickels
q+n = 46 coins total which solves to n = 46-q
25q = value of all the quarters in cents
5n = value of all the nickels in cents
25q+5n = value (cents) of all the coins of both types
25q+5n = 710 cents total = $7.10
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Apply substitution.
25q+5n = 710
25q+5(46-q) = 710
25q+230-5q = 710
20q+230 = 710
20q = 710-230
20q = 480
q = 480/20
q = 24
They have 24 quarters
This yields 25*q = 25*24 = 600 cents = $6.00 so far.
Use that value of q to find n
n = 46-q
n = 46-24
n = 22
They also have 22 nickels.
They have an additional 5n = 5*22 = 110 cents = $1.10
In total, they have 6.00+1.10 = 7.10 dollars which confirms we have the correct coin counts. Also, q+n = 24+22 = 46.
The line rises to the left so the slope is negative.
Slope = rise / run = (3 - 1) / (-4-3) = 2 / -7
Answer is -2/7 (A)
2/6 is the answer 1/2 1/2 0/2
