Question

How do you solve `7x + 1.5 = -6x - 3.7`?

Answer 1

`color(blue)(x= -2/5)`

Explanation:

I do not like calculation with decimal values so I try and get rid of them if I can.

Multiply both sides by 10 giving:

`70x+15=-60x-37`
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Add `color(blue)(60x)` to both sides giving:

`color(brown)(70xcolor(blue)(+60x)+15=-60xcolor(blue)(+60x)-37)`

`130x+15=0-37`

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Subtract `color(blue)(15)` from both sides

`color(brown)(130x+15color(blue)(-15)=-37color(blue)(-15)`

`130x=-52`

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Divide both sides by 130

`color(blue)(x=-52/130= -2/5)`

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`color(green)("Note that "2/5 = (2xx2)/(5xx2)=4/10= 0.4`