If two positive angles have a sum of 180 degrees, they are called supplementary angles.
If the number of adult tickets are taken as x then the number of children’s tickets can be taken as (89 — x ) then we can set up the equation
4.10(x) + 2.70 (89 — x) = 331.30
4.10x + 240.3 — 2.70x = 331.30
1.4x = 331.30 — 240.30
1.4x = 91
X = 65
Therefore 65 adult tickets and 24 children tickets as 89 — 65 is 24
Guppies: u
Goldfish: o
3 times as many guppies as goldfish
3*o = u (there are more guppies than goldfish)
o + u = 20
o = 20 - u
Substitute in (20 - u) for o in the first equation and solve:
3* (20 - u) = u
60 - 3u = u
60 = 4u
u = 15
He has 15 guppies. Then substitute in the number of guppies into either equation to find the number of goldfish:
o + u = 20
o + (15) = 20
o = 5
Hope this helps! :)
