Question 260259
I am not sure what 5 steps you use or your teacher wants, but here we go . . .
LABELS: x = base, x-4 = one side, x+6 = second side. Perimeter = a + b + c.
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VERBAL MODEL - the sum of the three sides must be greater than or equal to 26.
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ALGEBRAIC MODEL - x + x-4+x+6 >= 26
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SOLVE:
{{{x + x-4+x+6 >= 26}}}
combine like terms to get
{{{3x+2 >=26}}}
subtract to get
 {{{3x >=24}}}
divide to get
{{{x >=8}}}
So, 
x = 8,
x-4 = 4
x+6 = 14
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However, these side length don't make a triangle. The first base value that does work is 11.
x = 11
x-4 = 7
x+6 = 17
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CHECK
4+8+14 >= 26
16>= 26 [true].
However, these side length don't make a triangle.
11+7+17 >= 26
35>= 26 [true]
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so you want 11, 7, 17 sides