Answer:
A = 15u²
Step-by-step explanation:
Area of a Trapezoid Formula:

Plug in our values (h = 3, b1 = 7, b2 = 3)

Now we evaluate


An arithmetic sequence starts with one number and you add the common difference to the previous term to get the current term
So...
f(x)=mx+b
m=common difference
b=starting point
f(11)=125=11m+b
-
f(1)=5=1m+b
--------
120=10m
Divide both sides by 10
12=m
Your common difference is 12.
Answer:
h = A / ( 1/2 a - 1/2 b)
Step-by-step explanation:
A = ½ ah - ½ bh
Factor out an h
A = h( 1/2 a - 1/2 b)
Divide each side by ( 1/2 a - 1/2 b)
A / ( 1/2 a - 1/2 b) = h ( 1/2 a - 1/2 b)/ ( 1/2 a - 1/2 b)
A / ( 1/2 a - 1/2 b) = h
h = A / ( 1/2 a - 1/2 b)