Question

t power 2– 4t- 21 please help ​

Answer 1

Step-by-step explanation:

${x}^{2} - 4x - 21 = 0 \\ \\ {x}^{2} - 7x + 3x - 21 = 0 \\ \\ x(x - 7) + 3(x - 7) = 0 \\ \\ (x + 3)(x - 7) = 0 \\ \\ x = t \\ \\ t = - 3(not \: possible \: if \: t \: is \: time) \\ \\ t = 7$

Hope it helps

Answer 2

Answer:

t= -3 and t= 7

Step-by-step explanation:

See pic for better understanding

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