Answer:
25 girls
Step-by-step explanation:
Let
x denote number of boys
and
y denote number of girls
According to the statement that total 45 people came,
x+y = 45 => Eqn 1
And total paid amount was 175
So,
5x + 3y = 175 => Eqn 2
For solving, We will use the substitution method
So, from eqn 1
x = 45-y
Putting value of x in eqn 2
5(45-y) +3y = 175
225 - 5y + 3y = 175
-2y+225 = 175
-2y = 175-225
-2y = -50
2y = 50
y = 25
Putting y =25 in eqn 1
x+25 = 45
x = 45 - 25
x = 20
As y= 25
So, 25 girls came to the dance ..
Answer:

Step-by-step explanation:
Let's rewrite the left side keeping in mind the next propierties:


Therefore:

Now, cancel logarithms by taking exp of both sides:

Multiply both sides by
and using distributive propierty:

Substract
from both sides and factoring:

Multiply both sides by -1:

Split into two equations:

Solving for 
Add 4 to both sides:

Solving for 
Collect in terms of x and add
to both sides:

Divide both sides by e-2:

The solutions are:

If we evaluate x=4 in the original equation:

This is an absurd because log (x) is undefined for 
If we evaluate
in the original equation:

Which is correct, therefore the solution is:

Answer:
$11.52
Step-by-step explanation:
18% of 64 is 11.52