Using elimination method. Using substitution will cause some fraction problems.
c- child tickets
a- adult tickets
4a + 7c = $83
5a + 6c = $90
multiply by -5
-20a - 35c = -$415
20a + 24c = $360
-11c= -$55
c = $5 child tickets
4a + 7(5)= $83
4a + 35 = $83
4a = $48
a= $12 adult tickets
Answer:
Sister = 15 years old
Brother = 12 years old
Step-by-step explanation:
Right now, if the brother is B years old and the sister is S years old, B = (4/5)S because the ratio from brother to sister is 4:5, so if one unit is X, B = 4X and S = 5X
Three years ago, the brother was B-3 years old and the sister was S-3 years old. Keeping one unit as X, we have
B = 3X
S = 4X
B-3 = (3/4)(S-3)
Therefore, we have a system of equations
B = (4/5)S
B-3 = (3/4)(S-3)
Substitute (4/5)S for B into the second equation to only have one variable
(4/5)S - 3 = (3/4)(S-3)
(4/5)S - 3 = (3/4)S - 9/4
add 3 to both sides and subtract (3/4)S from both sides to isolate the variable and its coefficient
(1/20)S = 3/4
multiply both sides by 20 to isolate the S
S = 15
B = (4/5)S = 12
Answer:
A≈534.07
Step-by-step explanation:
A=2πrh+2πr^2
If they left 15% the tip should be
$11.40, making the total fee $87.40
Answer:
True
Step-by-step explanation:
