Same question
x+y=30
x is 1/5 of y
x=y/5
subsitute
y/5+y=30
multily both sidse by 5
y+5y=150
add
6y=150
divide both sides by 6
y=25
subsitute
x=y/5
x=25/5
x=5
the numbers are 5 and 25
Total ratio=9+11=20
number of girls=11/20*400
=220
Answer:



This might not be correct though. I'm only in middle school lol. I am sure about the last one.
The range is the ouutput from inputing the input
basically
25=k²+2k+1 and 64=k²+2k+1
the values that satisfy both equations (not at the same tim) are the valuess that are the domain
solve each
25=k²+2k+1
minus 25 both sides (or recognize the perfect square trinomial, but anyway)
0=k²+2k-24
factor
0=(k+6)(k-4)
set to zero
k+6=0
k=-6
k-4=0
k=4
k=-6 or 4
64=k²+2k+1
minus 64 both sides
0=k²+2k-63
facor
0=(k-7)(k+9)
set to zer
k-7=0
k=7
k+9=0
k=-9
k=-9 or 7
so the domain has the numbers
-9,-6,4,7
it seems we only want the positive square roots so
answer is {4,7} is the domain
Answer:
9
Step-by-step explanation: