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:
84 cm²
Step-by-step explanation:
Surface area of the polyhedron = the sum of the areas of each parts of the net = area of 2 triangles + area of each of the 3 rectangles
Area of 2 triangles:
Base = 4 cm
Height = 3 cm
Area of the 2 triangles = 2(½*base*height)
= 2(½*4*3) = 4*3 = 12 cm²
Area of rectangle with the following dimensions:
Length = 6 cm
Width = 4 cm
Area = length * width = 24 cm²
Area of rectangle with the following dimensions:
Length = 6 cm
Width = 5 cm
Area = length * width = 30 cm²
Area of rectangle with the following dimensions:
Length = 6 cm
Width = 3 cm
Area = length * width = 18 cm²
Surface area of the polyhedron = 12 + 24 + 30 + 18 = 84 cm²
Answer: The third one
Step-by-step explanation: I just did the question on edge. ,and I got it right.
