Hey there! :D
H + 9.7= -9.7
When you are trying to find a variable, you have to do the opposite (or reciprocal) on the other side.
So, since 9.7 is positive and being added to H, we will subtract it from the other side.
H + 9.7 (-9.7)= -9.7(-9.7)
H= -19.4
I hope this helps!
~kaikers
