Question

please say answer fast​

Answer 1

Answer:

a=3,a=4 is the correct answer

Answer 2

Question -

a²- 7a + 12

Required Answer -

$\red{\bigstar}\sf a ^{2} - 7a + 12 \large\leadsto{\tt\purple{ [ a-4][a-3 ] }}$

Step By Step Solution -

a²- 7a + 12 , now we need to replace 7a from the numbers which are factors of 12 and while adding or subtracting gives -7.

Factors of 12

• 12 and 1
• 2 and 6
• 3 and 4

Let's give a try to each ,

1) 12 and 1 ; 12 + 1 = 13 ☒ , 12 - 1 = 11 ☒

now by adding and subtracting 12 and 2 we are not getting -7

2) 2 and 6 ; 2 + 6 = 8 ☒ , 6 - 2 = 4 ☒

now by adding and subtracting 2 and 6 we are not getting -7

3) 3 and 4 ; 4 + 3 = 7 ☒ , -4 - 3 = -7 ☑

now by adding 4 and 3 we are not getting -7 but by subtracting -4 and 3 we are getting -7 its mean we will replace it with -4 and 3 .

$\begin{gathered}\begin{gathered}\begin{gathered}\begin{gathered} \\ \\ : \implies \displaystyle \sf \: {a}^{2} - 4a - 3a + 12 \\ \end{gathered} \end{gathered}\end{gathered} \end{gathered}$

$\begin{gathered}\begin{gathered}\begin{gathered}\begin{gathered} \\ \\ : \implies \displaystyle \sf \: ( {a}^{2} - 4a )- (3a + 12) \\ \end{gathered} \end{gathered}\end{gathered} \end{gathered}$

$\begin{gathered}\begin{gathered}\begin{gathered}\begin{gathered} \\ \\ : \implies \displaystyle \sf \: a( a - 4)- 3(a - 4) \\ \end{gathered} \end{gathered}\end{gathered} \end{gathered}$

Now we will take (a-4) and (a-3) common

$\begin{gathered}\begin{gathered}\begin{gathered}\begin{gathered} \\ \\ : \implies \displaystyle \sf \color{cyan}{ \: ( a - 4)(a- 3)} \\ \end{gathered} \end{gathered}\end{gathered} \end{gathered}$