25 degrees is the answer. CBE is supplementary to ABC. That means those two angles add up to 180 degrees.
Hello,
Let's assume n,n+1,n+2,n+3,n+4 the 5 numbers
n+(n+1)+...+(n+4)=5n+10=265
5n=265-10
5n=255
n=51
The 5th number is 51+4=55
The order of mathematical operation is MDAS.
M - multiplication
D - division
A - addition
S - subtraction
3 - 3 x 6 + 2
Multiplication : 3 x 6 = 18
Division: none
Addition : + 3 + 2 = 5 (combine positive numbers)
Subtraction : 5 - 18 = -13
3 - 18 + 2 = -13

is the only acute angle whose sin = 1/2. Therefore, cos (

) =