barry has 18 more marbles than heidi.if barry has 92 marbles,write and solve an equation to determine the number of marbles heidi has.



Answer :

bobeld
n= Heidi's marbles
92 - n =18   (Barry's 92 marbles - whatever Heidi has = 18 marbles difference)

92 -n +n = 18 +n   (I added n to each side)
92 = 18+n    
 92 -18 = 18-18 + n   (I subtracted 18 from both sides)
74 = n    Heidi has 74 marbles