Hi Lydia;
-2t≥100
Notice ≥ rather than ≤. When I was in 6th grade, the way we memorized the difference is, the alligator is going to eat the bigger one. The greater than or less than sign represents an alligator. The _ is part of the = sign.
-2t≥100
To isolate t, let's divide both sides by -2. Because of this act of division of a negative number, we must switch the sign...
(-2t)/(-2)≤(100)/(-2)
If we are adding or subtracting a negative, this would NOT be necessary. But multiplication or division of a negative number requires the switch.
t≤-50
t must always be equal or less than -50 for this equation to work.
Considering the original equation...
-2t≥100
-2(-50)≥100
100=100
It works.
Since t must always be equal to or less than -50, let's try a number which is less than...
(-2)(-100)>100
200>100
200 is greater than 100.
It works.
Let's try a number which is greater than -50.
(-2)(0)≥100
-2≥100
-2 is less than 100.
It does NOT work.
