Answer:
a) 7z³+2z²-2z+1
b)2x²+3x-8
Step-by-step explanation:
a) (7z³+4z-1)+(2z²-6z+2)
7z³+2z²-2z+1
b) (5x²-2x-1)-(3x²-5x+7)
5x²-2x-1-3x²+5x-7
2x²+3x-8
To start, the first thing you need to know is that when you add decimals, you must line the decimal up, meaning, if you were adding 2.7+4.1, you have to make sure 2 is lined up with 4, and 7 is lined up with 1 so that the decimals align. Then, you add straight down from right to left and you get 6.8 as your answer.
-- Kenny's weight is 6/7 of Melvin's weight.
-- Melvin's weight is 7/7 of Melvin's weight.
-- The ratio of Kenny's weight to Melvin's weight is (6/7) / (7/7) = 6/7 .