X = y + 12. You then substitute or plug in that from the first equation into the second equation. You get (y+12)+y=18, then you simplify to get your y value. In this case y = 3. The you can plug your y value into either equation. (x+3=18) or (x-3=12) or (x=3+12) either way you get x=15 and y=3.
Surface Area of the figure is 1208 square centimeters
a=20
b=13
c=12
d=5
e=8
Top face:
A1=a×e=20×8
ae=160
Bottom face:
A2(a+2d)×e=(20+2×5)×8=(20+10)×8=30×8
(a+2d)e=240
Front face:
Rectangle
a×c=20×12=240
Triangle:
12c×d=12×12×5=6×5=30
A3Rectangle +2 triangles
240+2×30=240+60=300
(a+d)c=300
Slant face:
A4=b×e=13×8=104
be=104
Total surface area
A=A1+A2+2(A3+A4)
A1=160
A2=240
A3=300
A4=104
Thus,
A=160+240+2(300+104)
A=400+2(404)
A=400+808=1208
Surface Area of the figure is 1208 square centimeters
What?
The slope can be found between two points by finding the change in values divided by the change in values.
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