Answer:

system of equations is used.
There are <u>21</u> children and <u>117</u> adults went to the film premiere.
Step-by-step explanation:
Given:
Mega Movies hosted a film premiere on Friday night. They charged $8 for adults and $4 for children. One hundred thirty-eight adults and children attended, and $1,020 was made in ticket sales.
Now, to find the children and adults went to the film premiere.
<u>Let the number of children went to premiere be </u>
<u />
<u>And let the number of adults went to premiere be </u>
<u />
So, total number of adults and children attended:

Now, the total amount made in ticket sales:

So, we use


system of equations to find the number of children and adults.
Substituting the value of
in equation (1):


<em>Subtracting both sides by 1104 we get:</em>
<em />
<em />
<em>Dividing both sides by -4 we get:</em>
<em />
<em />
<em>The number of children went to premiere = 21.</em>
Now, substituting the value of
in equation (1):

<em>The number of adults went to premiere = 117.</em>
Hence,

system of equations is used.
There are 21 children and 117 adults went to the film premiere.