IMG0 What is the integer t for which 32t+23t=26? What is the integer x for which 43+x=86+x ? Suppose that y>0 and 32+42+122=32+42+y2. Determine the value of y.
Solution
Multiplying both sides of the equation by 2⋅3=6, we obtain 6⋅32t+6⋅23t=6⋅26 or 4t+9t=156.
Simplifying, we obtain 13t=156 and so t=12. Alternatively, using a common denominator of 2⋅3=6, we obtain 2⋅32⋅2t+3⋅23⋅3t=26 or 64t+69t=26. Simplifying, we obtain $613t = 26andso13t = 6 ⋅ 26ort = 6 ⋅ 2 = 12. Multiplying both sides of the equation by
8,weobtain48(3+x) = 6 + xwhichsimplifiesto2(3+x) = 6 + x.Simplifyingfurther,weobtain6 + 2x = 6 + xandsox = 0. Alternatively, splitting each fraction into two pieces, we obtain
43+4x=86+8x.Since43=86,weobtain4x=8xandso8x = 4xorx = 0.Sincey > 0,theny2 = y. From the given equation, we obtain
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