Com que una equació és un equilibri, 

per a trobar una equació equivalent

FEM EL MATEIX ALS DOS MEMBRES

Sumar : «math xmlns=¨http://www.w3.org/1998/Math/MathML¨»«mstyle mathsize=¨12px¨»«mn mathvariant=¨bold¨»3«/mn»«mi mathvariant=¨bold¨»x«/mi»«mo mathvariant=¨bold¨»§#160;«/mo»«mo mathvariant=¨bold¨»-«/mo»«mo mathvariant=¨bold¨»§#160;«/mo»«mn mathvariant=¨bold¨»2«/mn»«mo mathvariant=¨bold¨»§#160;«/mo»«mo mathvariant=¨bold¨»=«/mo»«mo mathvariant=¨bold¨»§#160;«/mo»«mn mathvariant=¨bold¨»6«/mn»«mi mathvariant=¨bold¨»x«/mi»«mo mathvariant=¨bold¨»§#160;«/mo»«mo mathvariant=¨bold¨»+«/mo»«mo mathvariant=¨bold¨»§#160;«/mo»«mn mathvariant=¨bold¨»5«/mn»«mo mathvariant=¨bold¨»§#160;«/mo»«mo mathvariant=¨bold¨»§#160;«/mo»«mo mathvariant=¨bold¨»§#8660;«/mo»«mo mathvariant=¨bold¨»§#160;«/mo»«mn mathvariant=¨bold¨»3«/mn»«mi mathvariant=¨bold¨»x«/mi»«mo mathvariant=¨bold¨»§#160;«/mo»«mo mathvariant=¨bold¨»-«/mo»«mo mathvariant=¨bold¨»§#160;«/mo»«mn mathvariant=¨bold¨»2«/mn»«mo mathvariant=¨bold¨»§#160;«/mo»«mo mathvariant=¨bold¨ mathcolor=¨#FF0000¨»+«/mo»«mo mathvariant=¨bold¨ mathcolor=¨#FF0000¨»§#160;«/mo»«mn mathvariant=¨bold¨ mathcolor=¨#FF0000¨»2«/mn»«mo mathvariant=¨bold¨»§#160;«/mo»«mo mathvariant=¨bold¨»=«/mo»«mo mathvariant=¨bold¨»§#160;«/mo»«mn mathvariant=¨bold¨»6«/mn»«mi mathvariant=¨bold¨»x«/mi»«mo mathvariant=¨bold¨»§#160;«/mo»«mo mathvariant=¨bold¨»+«/mo»«mo mathvariant=¨bold¨»§#160;«/mo»«mn mathvariant=¨bold¨»5«/mn»«mo mathvariant=¨bold¨»§#160;«/mo»«mo mathvariant=¨bold¨ mathcolor=¨#FF0000¨»+«/mo»«mo mathvariant=¨bold¨ mathcolor=¨#FF0000¨»§#160;«/mo»«mn mathvariant=¨bold¨ mathcolor=¨#FF0000¨»2«/mn»«/mstyle»«/math»

Restar: «math xmlns=¨http://www.w3.org/1998/Math/MathML¨»«mstyle mathsize=¨12px¨»«mn mathvariant=¨bold¨»5«/mn»«mi mathvariant=¨bold-italic¨»x«/mi»«mo mathvariant=¨bold¨»§#160;«/mo»«mo mathvariant=¨bold¨»+«/mo»«mo mathvariant=¨bold¨»§#160;«/mo»«mn mathvariant=¨bold¨»6«/mn»«mo mathvariant=¨bold¨»§#160;«/mo»«mo mathvariant=¨bold¨»=«/mo»«mo mathvariant=¨bold¨»§#8201;«/mo»«mn mathvariant=¨bold¨»2«/mn»«mi mathvariant=¨bold-italic¨»x«/mi»«mo mathvariant=¨bold¨»§#160;«/mo»«mo mathvariant=¨bold¨»+«/mo»«mo mathvariant=¨bold¨»§#160;«/mo»«mn mathvariant=¨bold¨»3«/mn»«mo mathvariant=¨bold¨»§#160;«/mo»«mo mathvariant=¨bold¨»§#160;«/mo»«mo mathvariant=¨bold¨»§#8660;«/mo»«mo mathvariant=¨bold¨»§#160;«/mo»«mn mathvariant=¨bold¨»5«/mn»«mi mathvariant=¨bold-italic¨»x«/mi»«mo mathvariant=¨bold¨»§#160;«/mo»«mo mathvariant=¨bold¨ mathcolor=¨#FF0000¨»-«/mo»«mo mathvariant=¨bold¨ mathcolor=¨#FF0000¨»§#160;«/mo»«mn mathvariant=¨bold¨ mathcolor=¨#FF0000¨»2«/mn»«mi mathvariant=¨bold-italic¨ mathcolor=¨#FF0000¨»x«/mi»«mo mathvariant=¨bold¨»§#160;«/mo»«mo mathvariant=¨bold¨»+«/mo»«mo mathvariant=¨bold¨»§#160;«/mo»«mn mathvariant=¨bold¨»6«/mn»«mo mathvariant=¨bold¨»§#160;«/mo»«mo mathvariant=¨bold¨»=«/mo»«mo mathvariant=¨bold¨»§#160;«/mo»«mn mathvariant=¨bold¨»2«/mn»«mi mathvariant=¨bold-italic¨»x«/mi»«mo mathvariant=¨bold¨»§#160;«/mo»«mo mathvariant=¨bold¨ mathcolor=¨#FF0000¨»-«/mo»«mo mathvariant=¨bold¨ mathcolor=¨#FF0000¨»§#160;«/mo»«mn mathvariant=¨bold¨ mathcolor=¨#FF0000¨»2«/mn»«mi mathvariant=¨bold-italic¨ mathcolor=¨#FF0000¨»x«/mi»«mo mathvariant=¨bold¨»§#160;«/mo»«mo mathvariant=¨bold¨»+«/mo»«mo mathvariant=¨bold¨»§#160;«/mo»«mn mathvariant=¨bold¨»3«/mn»«/mstyle»«/math»

Multiplicar: «math xmlns=¨http://www.w3.org/1998/Math/MathML¨»«mstyle mathsize=¨12px¨»«mrow»«mfrac»«mrow»«mn mathvariant=¨bold¨»3«/mn»«mi mathvariant=¨bold¨»x«/mi»«mo mathvariant=¨bold¨»-«/mo»«mn mathvariant=¨bold¨»15«/mn»«/mrow»«mn mathcolor=¨#FF0000¨ mathvariant=¨bold¨»6«/mn»«/mfrac»«mo mathvariant=¨bold¨»=«/mo»«mfrac»«mrow»«mn mathvariant=¨bold¨»2«/mn»«mi mathvariant=¨bold¨»x«/mi»«mo mathvariant=¨bold¨»+«/mo»«mn mathvariant=¨bold¨»8«/mn»«/mrow»«mn mathcolor=¨#FF0000¨ mathvariant=¨bold¨»6«/mn»«/mfrac»«mo mathvariant=¨bold¨»§#8660;«/mo»«mn mathvariant=¨bold¨»3«/mn»«mi mathvariant=¨bold-italic¨»x«/mi»«mo mathvariant=¨bold¨»-«/mo»«mn mathvariant=¨bold¨»15«/mn»«mo mathvariant=¨bold¨»=«/mo»«mn mathvariant=¨bold¨»2«/mn»«mi mathvariant=¨bold-italic¨»x«/mi»«mo mathvariant=¨bold¨»+«/mo»«mn mathvariant=¨bold¨»8«/mn»«/mrow»«/mstyle»«/math»

Dividir: «math xmlns=¨http://www.w3.org/1998/Math/MathML¨»«mstyle mathsize=¨12px¨»«mrow»«mn mathvariant=¨bold¨»5«/mn»«mi mathvariant=¨bold-italic¨»x«/mi»«mo mathvariant=¨bold¨»=«/mo»«mn mathvariant=¨bold¨»15«/mn»«mo mathvariant=¨bold¨»§#8660;«/mo»«mfrac»«mrow»«mn mathvariant=¨bold¨»5«/mn»«mi mathvariant=¨bold¨»x«/mi»«/mrow»«mn mathcolor=¨#FF0000¨ mathvariant=¨bold¨»5«/mn»«/mfrac»«mo mathvariant=¨bold¨»=«/mo»«mfrac»«mn mathvariant=¨bold¨»15«/mn»«mn mathcolor=¨#FF0000¨ mathvariant=¨bold¨»5«/mn»«/mfrac»«/mrow»«/mstyle»«/math»