if ( r = - 1 ), ( s = 3 ), ( v = 0 ), and ( w = - \frac { 1 } { 2 } ), evaluate ( 7 s - 2 v + \frac { 2 w }…

if ( r = - 1 ), ( s = 3 ), ( v = 0 ), and ( w = - \frac { 1 } { 2 } ), evaluate ( 7 s - 2 v + \frac { 2 w } { r } ).\na) 20\nb) 15\nc) 22\nd) 45

if ( r = - 1 ), ( s = 3 ), ( v = 0 ), and ( w = - \frac { 1 } { 2 } ), evaluate ( 7 s - 2 v + \frac { 2 w } { r } ).\na) 20\nb) 15\nc) 22\nd) 45

Answer

Explanation:

Step1: Substitute the values

Substitute (r = - 1), (s = 3), (v = 0), (w=-\frac{1}{2}) into the expression (7s - 2v+\frac{2w}{r}). [ \begin{align*} &7\times3-2\times0+\frac{2\times(-\frac{1}{2})}{-1}\ \end{align*} ]

Step2: Calculate each term

Calculate each term separately.

  • For (7\times3), using multiplication (7\times3 = 21).
  • For (-2\times0), using multiplication (-2\times0 = 0).
  • For (\frac{2\times(-\frac{1}{2})}{-1}), first calculate (2\times(-\frac{1}{2})=-1), then (\frac{-1}{-1}=1).

Step3: Sum up the terms

Sum up the results of each term: (21 + 0+1).

Answer:

(22), so the answer is C.