They can be derived by using calculus(integration to be precise)
(its how pi is defined)
so that gives circumference
to get area , you use integration
that gives the area.
if you don't know calculus yet ,dont worry, just remember the formulae.
Parallel lines...means ur equations will have the same slope and different y int's.
x - 2y = 8....-2y = -x + 8....y = 1/2x - 4...slope is 1/2, y int is -4
2x + 4y = 12...4y = -2x + 12....y = -1/2x + 3...slope is - 1/2, y int is 3
not this one...different slopes
x - 2y = 8...slope is 1/2, y int is -4
2x - 4y = 12...-4y = -2x + 12...y = 1/2x - 3....slope is 1/2, y int is -3
same slope, different y int's.....these are parallel lines..but this is not ur graph because the graph has a negative slope.
x + 2y = 8....2y = -x + 8....y = -1/2x + 4..slope is -1/2, y int is 4
2x + 4y = 12...4y = -2x + 12....y = -1/2x + 3...slope is -1/2, y int is 3
same slope, different y int's...parallel lines...and ur y int's match the graph...this is ur answer <===
x + 2y = 8...slope is -1/2, y int is 4
2x - 4y = 12..slope is 1/2, y int is 3
different slopes, different y int....this has 1 solution and ur lines are not parallel...not this one
therefore, ur answer is : 3rd answer choice
Answer:
A 2 by 2 inch square has an area of 4 square inches.
If its area is increased by 21 inches, then its area equals 25 square inches.
To find the length of the side we take the square root of 25 square inches which is 5 inches.
Step-by-step explanation:
19.2 × 21 = 403.2
He drove a total of 403.2 miles to and from work in 21 days.
