Answer:
goldfish is 15 and guppies is 11
Step-by-step explanation:
Given data
let the number of goldfish be x
and the number of guppies be y
so
x+y= 25----------1
and
3x+4y= 86-------2
solve 1 and 2
x+y= 25
3x+4y= 86
from 1
x= 25-y
put this in 2
3(25-y)+4y= 86
75-3y+4y= 86
75+y= 86
y= 86-75
y=11
put y= 11 in 1
x+11= 26
x= 26-11
x= 15
Hence goldfish is 15 and guppies is 11
13.
230 per hour. multiply 230 by the number of hours to find total posters.
The equation is Total = 230 x hours written as T = 230x, where x is the number of hours.
you have the total, so replace t with the value and solve for x:
1265 = 230x
Divide both sides by 230:
x = 1265 / 230
x = 5.5 hours.
14.
Mean is the average. To find the average, add the four scores together and divide by 4.
The expression is Mean = ( score 1 + score 2 + score 3 + score 4)/4
Replace what is known:
20 = (25 + 15 + 18 + p)/4
Simpligy:
20 = (58 +p) /4
Multiply both sides by 4:
80 = 58 + p
Subtract 58 from both sides:
p = 80 - 58
p = 22
