12a=x
4a+6b=10
2a+3b=5
2a-4b=12
a-2b=6
2a+3b+1=a-2b
a+5b+1=0
a=-1-5b
2(-1-5b)+3b=5
-2-10b+3b=5
-2-7b=5
-7b=7
7b=-7
b=-1
-1-5*-1=a
-1+5=a
4=a
4*12=48
12a=48
Hope this helps :)
Answer:
4
Step-by-step explanation: it easy
The two parallel bases b1 and b2 are
b1 = 12
b2 = 9
the order of which base you pick doesn't matter
The height is h = 10 and it's perpendicular to each base.
The area is...
A = (1/2)*h*(b1+b2)
A = (1/2)*10*(12+9)
A = (1/2)*10*(21)
A = 5*21
A = 105
Final Answer: B) 105 square centimeters