Question

bobby had b marbles and charlie had c marbles.After bobby gave 6 marbles to charlie,bobby still had 18 more marbles than charlie. find c-b
a) 30
b) 12
c) 3
d) -12
e) -30

Answer 1

Bobby gives away six. At the end, he has b-6 marbles.
Charlie gains six. At the end, he has c+6 marbles.
b-6 is 18 greater than c+6. Written as an equation:
b-6 = c+6 + 18
b-6 = c + 24

You can solve for (c-b) by subtracting 24 from both sides and subtracting b from both sides:
c-b = -24-6
c-b = -30; e

Answer 2

@DDCamp thanx