Question

Find the 11th term from the last term (toward the first term) of AP:10,7,4,...,-62?

Answer 1

Answer:

$\huge{\pink{\boxed{\green{\sf{11th\:term\:from\:last=-32}}}}}$

Step-by-step explanation:

$\huge{\pink{\boxed{\green{\underline{\red{\sf{SOLUTION-}}}}}}}$

$\:\:\:\:\:{\orange{given}}$

${\pink{\boxed{\green{a=10}}}}$

${\pink{\boxed{\green{d=-3}}}}$

${\pink{\boxed{\green{l=-62}}}}$

${\blue{to\:find}}$

${\purple{\boxed{\red{11th\:term\:from\:end=?}}}}$

☆ According to given question:

$\to l = a + (n - 1)d \\ \to - 62 = 10 + (n - 1) \times ( - 3) \\ \to - 62 - 10 = (n - 1) \times ( - 3) \\ \to - 72 = (n - 1) \times ( - 3) \\ \to n - 1 = \frac{ - 72}{ - 3} \\ \to n - 1 = 24 \\ { \boxed{\to n = 25}}$

$\to a_{15} = a + 14d \\ \to a_{15} = 10 + 14 \times ( - 3) \\ \to a_{15} = 10 - 42 \\ { \boxed{\to a_{15} = - 32 }}\\ { \pink{ \boxed{ \green{\therefore so \: the \: 11th \: term \: from \: end \: is \: - 32}}}}$

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