Answer:
don't understand
but mean = <u>summation x</u>
total number
15=<u>7+4+5+2x+11</u>
5
15=<u>27+2x</u>
5
multiply both sides by 5
15×5=<u>2</u><u>6</u><u>+</u><u>2</u><u>x</u> ×5
5
75=26+2x
75-26=2x
<u>49</u>=<u>2x</u>
2. 2
x= 24.5
a resposta será c. Espero que isso ajude você.
<span> tan(x)/ cos(x)-sec(x)
tanx/(cosx-1/cosx)
tanx/cos^2x-1)--------------------1-sin^2x=cos^2x
-tanx/sin^2x
-(sinx/cosx)/sin^2x
-1/sinxcosx
multiply 2/2
-2/2sinxcosx-------------sin2x=2sincosx
-2/sin2x------------------1/sinx=cosecx
-2cosec2x</span>
