Al resolver (4 / 10 - 3 / 10 * 3 / 7 resulta?

Resolvemos :

<img src="https://tex.z-dn.net/?f=%5Cleft%28%5Cfrac%7B4%7D%7B10%7D-%5Cfrac%7B3%7D%7B10%7D%5Cright%29%5Cfrac%7B3%7D%7B7%7D%5C%5C%0A%5C%5C%0A%3D%5Cfrac%7B3%7D%7B7%7D%5Cleft%28%5Cfrac%7B1%7D%7B10%7D%5Cright%29%5C%5C%0A%5C%5C%0A%3D%5Cfrac%7B1%7D%7B10%7D%5Ccdot%20%5Cfrac%7B3%7D%7B7%7D%5C%5C%0A%5C%5C%0A%3D%5Cfrac%7B1%5Ccdot%20%5C%3A3%7D%7B10%5Ccdot%20%5C%3A7%7D%5C%5C%0A%5C%5C%0A%3D%5Cfrac%7B3%7D%7B7%5Ccdot%20%5C%3A10%7D%5C%5C%0A%5C%5C%0A%3D%5Cfrac%7B3%7D%7B70%7D" />

Conclusión :

<img src="https://tex.z-dn.net/?f=%28%5Cfrac%7B4%7D%7B10%7D-%5Cfrac%7B3%7D%7B10%7D%29%5Cfrac%7B3%7D%7B7%7D%3D%5Cfrac%7B3%7D%7B70%7D" />

¡SUERTE!