Let w be the number of weeks. He withdraws $25 per week, so in w weeks, he withdraws 25w. He starts with $500, so after w weeks he has 500 - 25w. He wants this amount to be at least $200. "At least" means "greater than or equal to."
500 - 25w >= 200
-25w >= -300
w <= 12
Answer: Keith can withdraw $25 per week for at most 12 weeks.
Answer:
2. Judy =$5
Ben= $4
Step-by-step explanation:
2. Let Judy = x and Ben = y
8x + 10y = 80
9x + 5y = 65
Solve these simultaneous equations.
8
x + 10
y = 80
18
x + 10
y = 130
Take the second equation away from the first equation
−
10
x = −
50
x = 5
This means that Judy gets paid $5 an hour.
Therefore, Ben gets paid $4 an hour.
Answer:
3. 24 quarters and 16 dimes
Step-by-step explanation:
3. Let the number of dimes = x and the number of quarters = y
Value Value
Type Number of of
of of EACH ALL
coin coins coin coins
-------------------------------------------
dimes x $0.10 $0.10x
quarters y $0.25 $0.25y
-------------------------------------------
TOTALS 40 $7.60
x + y = 40
0.10x + 0.25y = 7.60
Get rid of decimals by multiplying every term by 100:
10x + 25y = 760
So we have the system of equations:
x + y = 40
10x + 25y = 760
We solve by substitution. Solve the first equation for y:
x + y = 40
y = 40 - x
Substitute (40 - x) for y in 10x + 25y = 760
10x + 25(40 - x) = 760
10x + 1000 - 25x = 760
-15x + 1000 = 760
-15x = -240
x = 16 = the number of dimes.
Substitute in y = 40 - x
y = 40 - (16)
y = 24 quarters.
$1.60 + $6.00 = $7.60
I hope that helped, sorry for taking so long :-)
You want one of the values in the ratio to be one for a unit rate. First, write out the ratio. It is 70 miles/2 hours. It's better not to include decimal numbers when you write a ratio when you can, so we're going to make the hours the unit rate. To make 2 -> 1 hour, divide both sides of the ratio by 2. 70/2 = 35.
The unit rate is 35 mi./hr.
Hope that helped you.
Step-by-step explanation:
so blue and pink = purple Yellow and red = orange
