Answer:
B
Step-by-step explanation:
Let x be the unknown number
x×55%=121
x=121÷55%
x=220
So 121 is 55% of 220
The sum means addition.
Add the like terms together.
4x^3+2x^2-4x+3
+ 7x^3-4x^2+7x+8
4x^3 + 7x^3 = 11x^3
2x^2 + -4x^2 = -2x^2
-4x +7x = 3x
3 +8 = 11
The answer is : 11x^3 - 2x^2 + 3x + 11
The answer is the temperature goes down 2.8° every hour and the expression is x=-11.2/4 because 4 is how many hours between 6pm and 10pm and its -11.2 because that was how much the temperature dropped from 6pm to 10pm