Not the best handwriting but I hope it helped!
Answer:
156 square inches
Step-by-step explanation:
We are given the two quantities
Let
length = l = 13 inches
and
Width = w = 12 inches
The formula for the area of rectangle is:

where l is length and w is width
Putting the values of both that are given

so the area is 156 square inches ..
X = string section
y = brass section
x = y + 35
y = 29 .....there are 29 in the brass section
x = 29 + 35
x = 64...there are 64 in the string section
for a total of : 64 + 29 = 93 total musicians <==
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