Let's solve your equation step-by-step.
<span><span><span><span><span>3m</span>+<span>1m</span></span>−7</span>+<span>3m</span></span>=21
</span>Step 1: Simplify both sides of the equation.
<span><span><span><span><span>3m</span>+<span>1m</span></span>−7</span>+<span>3m</span></span>=21
</span><span>Simplify: (Show steps)
</span><span><span><span>7m</span>−7</span>=21
</span>Step 2: Add 7 to both sides.
<span><span><span><span>7m</span>−7</span>+7</span>=<span>21+7
</span></span><span><span>7m</span>=28
</span>Step 3: Divide both sides by 7.
<span><span><span>7m/</span>7</span>=<span>28/7
</span></span><span>m=4
</span>Answer:<span>m=<span>4</span></span>
Into 3 parts meand sivided by 3 means times 1/3
1/6 divided into 3 parts means 1/6 times 1/3=1/18
1/18 was in each mound
A is answer
For this case we have the following quadratic equation:

Where:

Its roots will be given by:

The roots are:

Answer:

79.881 hope this helps
i might be wrong