Question

In an Ap , the common difference is -4, and the seventh term (a7) is 4, then find the first term.

Answer 1

$\underline{ \fcolorbox{green}{pink}{ \huge{Solution :)}}}$

Given ,

Common difference = -4

Seventh term = 4

We know that , the nth term of an AP is given by

$\sf \large \fbox{ a_{n} = a + (n - 1)d}$

So ,

$\sf \mapsto a + 6(-4) = 4 \\ \\ \sf \mapsto</p><p>a + (-24) = 4 \\ \\ \sf \mapsto</p><p>a - 24 = 4 \\ \\ \sf \mapsto</p><p>a = 4 + 24 \\ \\ \sf \mapsto</p><p>a = 28</p><p>$

Hence , the first term of an AP is 28

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Answer 2

≡QUESTION≡

In an AP , the common difference is -4, and the seventh term is 4, then find the first term.

                                                     

║⊕ANSWER⊕║

GIVEN

Common difference = -4

a₇ = 4

$=> a + 6d = 4\\=> a + 6(-4) = 4\\=> a - 24 = 4$

=> a = 28

∴ The first term is 28.