Question

$\underline{ \boxed{\mathbb{\red{⛄Question♡࿐⛄}}}} \\ \\ if \: 12a \: + 3 b \: = 1 and \: 7 b - \: 2a \: = \: 9 \\ find \: the average \: (Arithmetic \: mean ) \: of \: a \\ and \: b$
please give correct answer
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Answer 1

Answer:

$\qquad\qquad\underline{\textsf{\textbf{ \color{magenta}{AnSwEr} }}}$

GIVEN:

⦿ 12a + 3b = 1

⦿ –2a + 7b = 9

Find Out :-

• What is the average (arithmetic mean) of a and b?

Solution :-

ADD the two equations to get: 10a + 10b = 10

Divide both sides by 10 to get: a + b = 1

As we know that :

$\red{ \boxed{\sf{Average =\: \dfrac{Sum\: of\: the\: numbers}{Total\: Numbers}}}}$

➙ (a + b)/2

➙ 1/2

➙ 0.5

Therefore, the average of a and b is 0.5 .

Answer 2

★given:-

$\implies \: 12a + 3b = 1 - - - (1) \\ \\ \implies \: - 2a + 7b = 9 - - - (2)$

★find:-

• average

★solution:-

addition of EQ( 1 )and (2 )to we get

$\implies \: 12a - 2a + 3b + 7b = 1 + 9 \\ \\ \\ \implies \: 10a + 10b = 10$

take common 10

$\implies {10}(a + b) = 10$

$\implies \: a + b = \frac{10}{10} \\ \\ \implies \: \: a + b = 1$-----(3)

$\implies \star \pink{average = \frac{sum \: of \: observation}{number \: of \: observation} }$

$\implies \: average = \frac{a + b}{2}$

EQ 3 value put

$\implies \red{ average \: = \frac{1}{2} }$

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I hope it helps you