Question 69439
1. 2/3 + 4t = 6t - 2/15 
Multiply thru by the lcm (least common multiple) to get rid of the fractions:
The lcm is 15.
10 +60t = 90t - 2
Add 2 to both sides; Subtract 60t from both sides.
30t=12
t=2/5
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2. 0.76 + 0.21t = 0.96t - 0.49 
Multiply thru by 100 to get rid of the decimals.
76 + 21t = 96t - 49
Add 49 to both sides: Subtract 21t from both sides.
125=75t
t=5/3
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3. 1/3x + 2/5 = 4/15 + 3/5x - 2/3 
It's not possible to tell if your x's are in the numerator or denominator.
I will assume you mean the following:
(1/3)x + (2/5) = (4/15) + (3/5)x - (2/3)
Multiply thru by 15 to get:
5x+6 = 4 +9x - 10
4x=-8
x=-2
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Cheers,
Stan H.