Find B if: (A+B)=(C+D)

[Catalin_a]

Guys... I need help how do I solve this simple equation ?

Find b if: (a+b)=(c+d)

[jg.allinsymbols]

Guys... I need help how do I solve this simple equation ?

Find b if: (a+b)=(c+d)

The parentheses for the lefthand and right hand members are not needed since nothing else on either side interferes with communication or meaning.

a+b=c+d.
Add the additive inverse of a to both sides and you are done.

[Catalin_a]

Thank you for reply, but how can I add the additive inverse of a to both sides when a is only on one side.

Can some one please solve this, I will have more sense if I can see it solved.

Please excuse my english, I am not an english speaker.

[jg.allinsymbols]

Thank you for reply, but how can I add the additive inverse of a to both sides when a is only on one side.

Can some one please solve this, I will have more sense if I can see it solved.

Please excuse my english, I am not an english speaker.

Surely, a is on one side but not the other. The number a and its additive inverse are different numbers. You want to add THE ADDITIVE INVERSE of a to BOTH SIDES of the equation so that you can eliminate a from one side and to maintain equality.

Essentially you want to subtract a from both sides. The idea is that a + -a = 0

[maggiemagnet]

You can see examples for one-variable equations here and for "literal" equations (like yours) here.

[karadimos]

A + B = C + D
subtract A from both sides

B = C + D - A

Mark Karadimos
www.mathguide.com