Math I need help

Question

Leo had twice as many stickers as John at first. Leo gave away three times as many stickers as John. John was left with 10 fewer than the number of stickers he gave away. Leo had 15 stickers in the end. How many stickers did John have at first?

Answer 1

John originally had 60 cards

L=2J Leo originally had twice as many as John

x = 3y where x= how many Leo gave away. y= how many John gave away

L-x = 15= cards Leo had after giving away x cards

substitute 2J for L to get

2J-x = 15

substitute 3y for x to get

2J-3y = 15

add 3y to both sides

2J = 15+3y

y-10=J-y John is left with 10 less than what he gave away

add y to both sides

2y-10 = J

J= 2y-10

multiply by 2

2J = 4y-20

15+3y = 4y-20

y = 35. John gave away 35 cards

J=2(35)-10 = 60 = the cards John originally had

L=2J = 120 = the cards Leo originally had

x=3y = 3(35) = 105 = cards Leo gave away

120-105 = 15 cards Leo had after giving away 105