Question

} ৭ + ৭ + ৭ = ১ X ৭ ২৪৭ -এর আগের এবং পরের সংখ্যা দুটি লিখে > বা < চিহ্ন দাও।t
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Answer 1

Solution -

We Have ,

\begin{gathered} \large \sf{a_{5} +a_{7} = 52}\\ \\ \large \sf{ = a + 4d + a + 6d= 52}\\ \\ \large \sf2a + 10d \: \: - - - (1)\\ \\ \large \sf{a_{11} = a + 10d = 46} \\ \\ \end{gathered}

a

5

+a

7

=52

=a+4d+a+6d=52

2a+10d−−−(1)

a

11

=a+10d=46

♠ Multiplying Both Sides by 2 :

\begin{gathered}\large :\longmapsto\sf 2a + 20d = 92\: \: - - - (2) \\ \end{gathered}

:⟼2a+20d=92−−−(2)

♠ Subtracting (1) From (2) , We get :-

\begin{gathered}\sf10d = 40 \\ \\ \sf d = \cancel{\frac{40}{10} }\\ \\ \purple{ \Large :\longmapsto \underline {\boxed{{\bf d = 4} }}}\end{gathered}

10d=40

d=

10

40

:⟼

d=4