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Mental solution
From 74, subtract 26.  The difference,  74-26 = 48,  is 3 times the smaller number.
Hence, the two numbers are   = 16  and  2*16+26 = 32+26 = 58.    ANSWER
CHECK.  16 + 58 = 74.    ! Precisely correct !
Solved.
Algebra solution
Let x be the smaller number.  
Then the other number is  2x+26.
The equation is
    x + (2x + 26) = 74
Simplify and solve
    x + 2x = 74 - 26
    3x = 48
     x =  = 16,
giving you the same answer.
Solved.
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Notice that the  Algebra solution  follows step-in-step the  Mental solution.
They both are  EQUIVALENT.