How to solve 8-2[(5-3)^2 -1]= with steps ^2 is for the power of 2

Ill mark the brainliest if you me with the these three questions 7,8,9

The measure of one angle of an octagon is two times smaller that of the other seven angles. what is the measure of each angle?

With this question substitute t=3 and t=5 to determine if the two expressions are equivalent. 4(t + 3) 4t+12 which statements are true? check all that apply. a. the value of both expressions when t =5 is 32. b. the two expressions are not equivalent. c. the value of both expressions when t=3 is 15. d. the value of both expressions when t=5 is 23. e. the two expressions are equivalent. f. the value of both expressions when t=3 is 24.