Question

Simplify and give reasons:
${(-2)}^7$

• A. $-128$
• B. $128$
• C. $-28$
• D. None of these

Answer 1

The correct option is A $-128$

$(-2{)}^7$

$=(-1\ast 2{)}^7$

$=(-1{)}^7(2{)}^7$ $\because (ab{)}^m=a^m\ast b^m$

$=-1\ast 2^7$

$=-2^7$

$=-128$