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The solution to (d+4)^2=9 is D=

User Valdo
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2 Answers

2 votes
Answer
d = -1 or d = -7
User JEricaM
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7 votes

Answer:


\boxed{\sf d = -1 \ \ \ or \ \ \ d = -7}

Explanation:


\sf Solve \: for \: d \: over \: the \: real \: numbers: \\ \sf \implies {(d + 4)}^(2) = 9 \\ \\ \sf Take \: the \: square \: root \: of \: both \: sides: \\ \sf \implies \sqrt{ {(d + 4)}^(2) } = √(9) \\ \\ \sf 9 = {3}^(2) : \\ \sf \implies \sqrt{ {(d + 4)}^(2) } = \sqrt{ {(3)}^(2) } \\ \\ \sf \implies d + 4 = \pm 3 \\ \\ \sf \implies d + 4 = 3 \: \: \: \: \: or \: \: \: \: \: d + 4 = - 3 \\ \\ \sf Subtract \: 4 \: from \: both \: sides: \\ \sf \implies d + (4 - 4)= 3 - 4 \: \: \: \: \: or \: \: \: \: \: d + (4 - 4) = - 3 - 4 \\ \\ \sf \implies d = - 1 \: \: \: \: \: or \: \: \: \: \: d = - 7

User NikLanf
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