Answer:
x = 19
Step-by-step explanation:
Trapezium area formula: [tex]\frac{a+b}{2} * h[/tex], where a & b are the two bases.
Now, if we plug in our known values, we can solve for the missing base.
[tex]\frac{5 + x}{2} * 4 = 48[/tex]
[tex]\frac{5 + x}{2} = 12\\\\5 + x = 24\\\\x = 19[/tex]
