Question

factorize t^2-4t-21 by spliting middle term

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Answer 1

Step-by-step explanation:

• First write the given equation

$\\\qquad\quad\sf\longrightarrow t^2-4t-21=0$

• factorise

$\\\qquad\quad\sf\longrightarrow t^2-7t+3t-21=0$

$\\\qquad\quad\sf\longrightarrow t (t-7)+3 (t-7)=0$

$\\\qquad\quad\sf\longrightarrow (t-7)(t+3)=0$

$\\\qquad\quad\sf\longrightarrow t-7=0\quad or\quad t+3=0$

$\\\qquad\quad\sf\longrightarrow t=7\quad or\quad t=-3$