Question

solve the following equation:-
a. 3(n-5)=21
b. -4(2+x)+8

Answer 1

a )         3 ( n - 5 ) = 21                  expand on the L H S
         3 n - 3 * 5  = 21          take 3*5 on to RHS
      =>    3 n  = 21 + 15 = 36      => n = 36 / 3 = 12

b )    - 4 (2 + x ) = 8        expand LHS 
         -4*2 - 4 * x = 8      =>  -8 - 4 x = 8    =>  -4 x = 8 + 8 = 16 
     => x = 16 / (- 4)      = - 4

Answer 2

1. 3(n-5)=21
=> 3n-15 = 21
=> 3n =21+15
=> 3n = 21+15 
=> n= 36/3
=> n= 12

2. -4 (2+x)+ 8 = 0
=> -8 - 4x + 8 = 0
=> -4x=0
=> x= -0/4
=> x= 0