Question

$t {}^{2} + 4t = 21$
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Answer 1

Answer:

t²+4t = 21

t²+4t-21 = 0

t²+7t-3t-21 = 0

t(t+7)-3(t+7) = 0

(t+7)(t-3) = 0

Either t+7 = 0 or t-3 = 0

t+7 = 0 t-3 = 0

t = -7 t = 3

t = -7,3

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