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(1/3)*(21*x+21)-8 = (-3/5)*(35*x-35) // - (-3/5)*(35*x-35)
(1/3)*(21*x+21)-((-3/5)*(35*x-35))-8 = 0
(1/3)*(21*x+21)+(3/5)*(35*x-35)-8 = 0
1/3*(21*x+21)+3/5*(35*x-35)-8 = 0
1/3*(21*x+21)+3/5*(35*x-35)-8 = 0
28*x-14-8 = 0
28*x-22 = 0
28*x-22 = 0
28*x-22 = 0 // + 22
28*x = 22 // : 28
x = 22/28
x = 11/14
x = 11/14
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