1. ## equation

a+8=12

t+(-3)=8

2. Originally Posted by dianna
a+8=12
You have $\displaystyle a+8=12$.

If two things are equal if you take the same thing from both the two results
are still equal.

So here we take (subtract) $\displaystyle 8$ form $\displaystyle a+8$ and also from $\displaystyle 12$, and the two results will be equal:

$\displaystyle (a+8)-8=12-8$

which gives:

$\displaystyle a=4$.

t+(-3)=8
This is the same thing as: $\displaystyle t-3=8$

Here we do the same sort of thing, we add $\displaystyle 3$ to $\displaystyle t-3$ and $\displaystyle 8$ to get:

$\displaystyle (t-3)+3=8+3$

which gives:

$\displaystyle t=11$

RonL

3. Originally Posted by dianna
a+8=12

t+(-3)=8
Whatever you do to one side of the equation, you must do to the other:
$\displaystyle a + 8 = 12$

$\displaystyle a + 8 - 8 = 12 - 8$

$\displaystyle a = 4$

=================================

$\displaystyle t+(-3)=8$

$\displaystyle t - 3 = 8$

$\displaystyle t - 3 + 3 = 8 + 3$

$\displaystyle t = 11$

-Dan