i need help with math problems

Question

Kevin, Eric, Emily and Vicky collect Pokémon cards. They have a total of 170 cards.

Eric has two less than half as many as Kevin’s cards. Emily has seven more cards than

Eric. Vicky has 28 less than half the sum of Kevin and Emily’s cards. How many cards

does each have?

Answer 1

k+r+e+ v = 170

r= k/2 - 2

e= r+7 = k/2-2+7

v= k/2+e/2 -28 = k/2+(k/2-2+7)/2-28

k + k/2-2 + k/2-2+7 + k/2 +(k/2-2+7)/2 -28 = 170

2k+k-4 +k-4+14 +k + k/2 -2+7 -56 = 340

5.5k =340+45

k = 385/5.5 = 77/1.1 = 770/11 = 70 cards for Kevin

r =70/2-2 = 33 cards for Eric

e =33+7 = 40 cards for Emily

v= 35+20-28 =27 card for Vicky

70+33+40+27 = 170