9514 1404 393
Answer:
Step-by-step explanation:
If we want the new line to be written in slope-intercept form, we need to find the new value of the y-intercept. The equation of the line is ...
y = mx +b . . . . . . . for slope m and y-intercept b
Solving for b gives ...
b = y -mx . . . . . . . subtract mx from both sides.
The values of x and y come from the point we want the line to pass through. The value of m will be the same for the parallel line as for the given line: 4. For the perpendicular line, it will be the opposite reciprocal of this: -1/4.
<u>Parallel line</u>
b = 6 -4(3) = 6 -12 = -6
y = 4x -6
Perpendicular line
b = 6 -(-1/4)(3) = 6 +3/4 = 27/4
y = -1/4x +27/4
We will caluclate the cost per gallon first. Then, we will multiply the new quantity by this cost, so we get the new cost.
As we are told that 6 gallons costs 26.58, we can divide 26.58 by 6 to calculate the cost per gallon. It would be
Now we multiply this quantity by 18, so we get the cost of 18 gallons. It would be
so the cost of 18 gallons is 79.74