# Question 97873

Jan 29, 2017

#### Answer:

$d = 6$

#### Explanation:

Given:$\text{ } 2 d - 5 = 7$

Determine the value of $d$

Add $\textcolor{m a \ge n t a}{5}$ to both sides. This turns the 5 on the left of the = into 0

$\textcolor{g r e e n}{2 d - 5 = 7 \text{ "->" } 2 d - 5 \textcolor{m a \ge n t a}{+ 5} = 7 \textcolor{m a \ge n t a}{+ 5}}$

But $- 5 + 5 = 0$ giving:

$\text{ "->" } \textcolor{g r e e n}{2 d + 0 = 12}$

Divide both sides by $\textcolor{m a \ge n t a}{2}$. This turns the 2 in $2 d$ into 1

$\text{ "color(green)( ->" } \frac{2}{\textcolor{m a \ge n t a}{2}} \times d = \frac{12}{\textcolor{m a \ge n t a}{2}}$

But $\frac{2}{2} = 1$ giving

" "color(green)(->" "1xxd=6)#
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$d = 6$