Question

34 + 32 + 30 + ... + 10.

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Answer 1

Answer:

106

Step-by-step explanation:

34 + 32 + 30 + 10

= 66 + 30 + 10

= 96 + 10

= 106

Answer 2

$\large\sf\underline\red{GIVEN:-}$

$\large\tt\purple{a=34}$

$\large\tt\purple{d=32-34=-2}$

$\small\tt\green{Let\:the\:nth\:term\:of\:the\:AP\:is\:10}$

$\therefore$$\large\tt\orange{an=10}$

$\longrightarrow$$\small\tt\red{a+(n-1)d=10}$

$\longrightarrow$$\small\tt\red{34+(n-1)(-2)=10}$

$\longrightarrow$$\small\tt\red{(n-1)(-2)=-24}$

$\longrightarrow$$\small\tt\red{n-1=12}$

$\longrightarrow$$\small\tt\red{n=13}$

$\small\sf\green{The\:sum\:of\:n\:terms\:of\:an\:AP\:is\:given\:by}$

$\longrightarrow$$\large\sf\pink{Sn=\frac{n}{2}(a+l)}$

$\longrightarrow$$\large\sf\pink{S13=\frac{13}{2}(34+10)}$

$\longrightarrow$$\large\sf\pink{S13=\frac{13}{2}(44)}$

$\longrightarrow$$\large\sf\pink{S13=13×22}$

$\longrightarrow$$\large\sf\pink{S13=286}$