How do you solve #2x-3+4=3#?

1 Answer
Mar 18, 2018

#x=1#
Used first principles. The shortcut approaches are only remembering the result of first principles.

Explanation:

We have only 1 unknown and 1 equation. So it is solvable. The equation count has to be the same as the count of 'different' unknowns.

Given: #2x-3+4=3#

Method:

Step 1:
Simplify as far as you are able.

Step 2:
Isolate (get on its own) the term with #x# in it. That is, have #2x# on one side of the = and everything else on the other side.

Step 3:
Get #x# on its own on one side of the = and everything else on the other side.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#color(blue)("Step 1")#

Deal with the -3+4

#color(green)(2xcolor(red)(-3+4)=3color(white)("dd")-> color(white)("ddd") 2xcolor(red)(+1)=3#
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#color(blue)("Step 2")#

Subtract #color(red)(1)# from both sides. This turns the +1 into 0

#color(green)(2x+1=3color(white)("dddd") ->color(white)("dddd") 2x+1color(red)(-1)color(white)("d")=color(white)("d")3color(red)(-1))#

#color(green)(color(white)("dddddddddddd.")->color(white)("dddd")2x+color(white)("d.")0color(white)("d.d")=color(white)("dd")2 )#
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#color(blue)("Step 3")#

Divide both sides by #color(red)(2)#. This turns the 2 from #2x# into 1 and 1 times anything does not change its value.

#color(green)(2x=2 color(white)("ddddddd")->color(white)("ddd")2/color(red)(2)x=2/color(red)(2)#

#color(green)(color(white)("ddddddddddd.d")->color(white)("ddd")x=1)#