Answer:
I am not sure what are we supposed to do but I guess we have to solve it?
0=0
Step-by-step explanation:
first rearrange the formula to get all r's on one side so it's gonna be:
4r-4r=-15+19-4
we really come to a closed end here because 4r-4r=0
it's gonna be 0=-15+19-4
0=0
Mkae sure you copied the question correctly
p.s: I'm not sure
