| x + a | = | x + a | As given in the question x=3 or x=9, replace first x by 3 and the other x by 9 | 3 + a | = | 9 + a | 3 + a = - ( 9 + a) 3 + a = -9 - a (Solving for a ) 2a = -12 a = -12/2 a= -6 now, | x + a | = | 3 - 6 | = |-3| = 3 | x + a | = | 9 - 6 | = |3| = 3 Therefore, the answer is | x - 6 | = 3
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, and then to know the value of r we just simply have to calculate the square root of 9, which is 3.