-4(7a+5)= -160
=>4(7a+5)= 160 ( Removing the negative signs by switching the sides )
=>4(7a+5)/4= 160/4 ( Dividing both sides by 4 )
=>7a+5= 40
=>7a+5-5= 40-5 ( Subtarcting 5 from both sides )
=>7a= 35
=>7a/7= 35/7 ( Dividing both sides by 7 )
Therefore, a=5 (Answer)