Question

2.8 over 4 = 7 over x

Answer 1

Starting with the equation:

$\frac{2.8}{4}=\frac{7}{x}$

Multiply both sides by 4x:

$\begin{gathered} \frac{2.8}{4}\cdot4x=\frac{7}{x}\cdot4x \\ \Rightarrow\frac{2.8\cdot4\cdot x}{4}=\frac{7\cdot4\cdot x}{x} \\ \Rightarrow\frac{4}{4}\cdot2.8\cdot x=\frac{x}{x}\cdot7\cdot4 \\ \Rightarrow2.8\cdot x=7\cdot4 \end{gathered}$

Notice that after multiplying both sides by 4x, each expression was simplified as a fraction, since 4/4 = 1 and x/x=1 for every x different from 0.

Now, simplify the product 7 times 4:

$2.8x=28$

Divide both sides by 2.8:

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