These videos might help you
https://www.khanacademy.org/math/algebra/systems-of-linear-equations/systems-of-linear-equations-wor...
He saves $200 (the amount of change over the original amount $500
200/500 = 2/5 and 2/5 = 40% (divide 2 by 5 and get .4 which = 40%)
40% discount is the answer to your question
Answer:
P = -12xy - 56y - 42x + 8
Step-by-step explanation:
P = 2L + 2W
P = 2(4 - 7(3x + 4y)) + 2(3x(-2y))
P = 8 - 14(3x + 4y) + 6x(-2y)
P = 8 - 42x - 56y - 12xy
P = -12xy - 56y - 42x + 8
Answer:
40
Step-by-step explanation:
add 21 + 20
hope this helps :)