There are several solutions. One is
[1, 5, 9, 4], [4, 2, 6, 7] and [7, 3, 8, 1]
A Quadrilateral.
11x = 10x-19 Subtact 10x fromboth sides:- x = -19
3x+7=19 3x=12 minus 7 from both sides x=4 divide by three on both sides leaving just what x equals
7x + 19 = -2x + 55Add 2x to both sides:9x + 19 = 55Subtract 19 from both sides:9x = 36Divide both sides by 9x = 4
-12 + c = 19 Add 12 to both sides: c = 19+12 = 31
There are 17 triangles in a 19 sided polygon
12
x +8=19 subtract 8 from both sides x=11
4a-13 = 19 Add 13 to both sides: 4a = 32 Divide both sides by 4 to find the value of a: a = 8
-x + 17 = 19 Subtract -17 from both sides: -x = 2 Multiply both sides by -1: x = -2
19 = f + 5 Subtract 5 from both sides: 14 = f
9d-19=6d+2 ... add 19 to both sides and subtract 6d from both sides... 9d-6d=2+19 3d=21 d=21/3 d=7