Answer:

Step-by-step explanation:
Given
--- candles melted

--- time to melt
Required
The time since the first was lit
If 1 candle melts in 4 hours, 2 candles will melt in 8 hours.
i.e.



For the 3rd candle that has melted, 4 inches
First, calculate the fraction that melt



The time to melt is:



So, the required time is:


Convert to minutes



We need to write system of equations for this problem. Reading text we write 1 equation by 1.
first lets name our variables
x - Kiana cards
y - Gary cards
z - Monty cards
m - Willa cards
x = y-3 which we can write as y = x+3
z = x + 7
m = 2z
x + y + z + m = 74
I think easiest way to solve this is to express all variables in last equation and solve for x.
x + x+3 + x + 7+ 2x + 14= 74
5x = 50
x = 10
now we just calculate cards given to each friend
y = 13
z = 17
m = 34
Answer:
y-5 = -3x
or
y = -3x+5
Step-by-step explanation:
We can use the point slope form of the equation
y-y1 = m(x-x1) where m is the slope and (x1,y1) is a point on the line
y-5 = -3(x-0)
y-5 = -3x
We can change it to slope intercept form y= mx+b by adding 5 to each side
y-5+5 = -3x+5
y = -3x+5
18
First you want to change the 20% into a decimal which is .20
Next you want to multiply 90 by .20 because that will give you the answer for 20% of 90
90x.20=18
Hope that helps