Question

$2 \div 7(l - 9 ) + l \div 3 = 3$
​

Answer 1

Step-by-step explanation:

Aligned equations

Often people want a series of equations where the equals signs are aligned. To get this, use \begin{align}…\end{align}. Each line should end with \\, and should contain an ampersand at the point to align at, typically immediately before the equals sign.

For example,

√

37

=

√

732−1

122

=

√

732

122

⋅

732−1

732

=

√

732

122

√

732−1

732

=

73

12

√

1−

1

732

≈

73

12

(1−

1

2⋅732

)

is produced by

\begin{align}

\sqrt{37} & = \sqrt{\frac{73^2-1}{12^2}} \\

& = \sqrt{\frac{73^2}{12^2}\cdot\frac{73^2-1}{73^2}} \\

& = \sqrt{\frac{73^2}{12^2}}\sqrt{\frac{73^2-1}{73^2}} \\

& = \frac{73}{12}\sqrt{1 - \frac{1}{73^2}} \\

& \approx \frac{73}{12}\left(1 - \frac{1}{2\cdot73^2}\right)

\end{align}