Question

The expression [(-7) ³ - (-7³)] - [(-7) ² + 7²] results in

a) -784
b) -686
c) -98
d) -49

Answer 1

`BASIC \: \: ALGEBRA \\ \\ \\ Given \: \: expression \: - \\ ( {( - 7)}^(3) - ( { - 7)}^(3) ) - ( {( - 7)}^(2) + {(7)}^(2) ) \\ \\ = \: \: 0 \: - \: ( {( - 7)}^(2) + {(7)}^(2) ) \\ \\ = \: \: 0 \: - (49 + 49) \\ \\ = \: \: 0 - 98 \\ \\ \\ = \: \: - 98 \: \: \: \: \: \: \: \: \: \: Ans.`

Answer 2

[(-7)(-7)(-7) + (-7)(-7)(-7)] - [(-7)(-7) + (7)(7)]
(-343 + -343) - (49 + 49)
-686 - 98 = -784
The answer is a) -784 :)