The answer is :
c. (x+1)²=20
To check:
(x+1)²=20 (a+b)²=a²+2ab+b²
x²+2x+1=20
x²+2x=20-1
x²+2x=19
It takes about 4 days for the temperature to decrease by 9°F.
An equation is an expression that shows the relationship between two or more variables or numbers.
Let x represent the number of days. Given that the temperature drop decreased by 1 1/2°F each day (- 1 1/2), for it to decrease by 9°F (-9):
-1 1/2 * x = -9
-1.5x = - 9
x = 4 days
It takes about 4 days for the temperature to decrease by 9°F.
