5x-7y=14
-5x -5x
^
Subtract 5x from both sides
-7y=-5x+14
Divide by -7 by all of the numbers
y=-5/7x-2
Answer: C.-1.5
Step-by-step explanation:
Given: The burning time of a very large candle is normally distributed with mean
of 2500 hours and standard deviation
of 20 hours.
Let X be a random variable that represent the burning time of a very large candle.
Formula: 
For X = 2470

So, the z-score they corresponds to a lifespan of 2470 hours. =-1.5
Hence, the correct option is C.-1.5.
Step 1. Combine like terms
Step 2. Subtract 7 from both sides
Step 3. Divide 6 from both sides
Final answer: x=1/6
They were 1 mile away from each other.
4-3=1 mile
Remark
I think you want us to do both 3 and 4
Three
QR is 4 points going left from the y axis + 2 points going right from the y axis.
QR = 6 units long.
RT is 4 units above the x axis and 3 units below the x axis
RT = 7 units long
TS = 3 units. For this one you just go from T to S. The graph really helps you. You just need to count.
Problem 4
You need to find the area of the combined figure. You could do it as a trapezoid, which might be the easiest way. I'll do that first.
Area = (b1 + b2)*h/2
Givens
B1 = QR = 6
B2 = UT + TS = 6 + 3 = 9
h = RT = 7
Area
Area = (6 + 9)*7/2
Area = 15 * 7 / 2
Area = 52.5
Comment
You could break this up into a rectangle + a triangle
Find the area of QRTU and add the Area of triangle RTS
<em>Area of the rectangle </em>= L * W
L = RT = 7
W = QR = 6
Area = 7 *6 = 42
<em>Area of the triangle</em> = 1/2 * B * H
B = TS = 3
H = RT =7
Area = 1/2 * 3 * 7
Area = 1/2 * 21
Area = 10.5
Total Area = 42 + 10.5 = 52.5 Both answers agree.