Marilyn A. answered 11/07/16
Tutor
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Looking forward to helping students reach their potential.
let s= cost of senior tickets and c=cost of children tickets
2 children and 4 senior tickets sold for $80 : 2c + 4s=80 this equation can be reduce to c + 2s = 40 by dividing all through by 2
7 children and 5 senior tickets sold for $145: 7c + 5s=145
your 2 equations are below and you can either use the substitution or elimination method to solve for c and s
c + 2s=40......equation 1
7c + 5s=145....equation 2
using the elimination method
7(c + 2s=40) = 7c + 14s = 280
-1(7c + 5s=145)= -7c - 5s = -145
-1(7c + 5s=145)= -7c - 5s = -145
subtract 9s = 135
divide s=15
substitute s=15 into equation 1; c +2(15)=40
c+30=40
subtract 30 from both sides c=10
therefore;
senior tickets cost $15 and children tickets cost $10
Proof
9s + 9c =225
9(15) + 9(10) = 135 + 90=225