Question

$3(y - 5) = 21$
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Answer 1

$3(y - 5) = 21$

$3y - 15 = 21$

$3y = 21 + 15$

$3y = 36$

$y = \frac{36}{3}$

$y = 12$

Answer 2

$3(y - 5) = 21 \\ \\ = > y - 5 = \frac{21}{3} \\ \\ = > y - 5 = 7 \\ \\ = > y = 7 + 5 \\ \\ = 12.$