Answer:
144
Step-by-step explanation:
20×12=240
add 4 to 20 and 12
makes a new rectangle 24×16
24×16=384
384-240=144
Answer:
x=-5/6
Step-by-step explanation:
The sum of the first n natural numbers and 0=
n*(n+1)/2
First you transform the expression and then evaluate the power