AP EAMCET202017 Sep 2020Evening ShiftMathematicsTrigonometric Ratios & IdentitiesActual
( 9^ - 27^ - 63^ + 81^ = )
Options
- A1
- B2
- C3
- D4
Correct answer
D. 4
Step-by-step solution
( aligned & 9^ - 27^ - 63^ + 81^ & = 81^ + 9^ - ( 63^ + 27^ ) & = 9^ + 9^ - ( 27^ + 27^ ) & = ^2 9^ + ^2 9^ 9^ 9^ - ^2 27^ + ^2 27^ 27 27 & = 1 9^ 9^ - 1 27^ 27^ & = 2 18^ - 2 54^ =2 54- 18 54 18 & = 4 36 18 36 18 =4 aligned )