There’s an invisible 1 in front of the minus sign and an invisible 1 in front of the variable.
-1(r+4)=-3 —> -1 times 1r = -1r. -1 times 4 = -4
Multiply inside the parentheses.
-1r-4=-3
Now add 4 to both sides.
-1r-4=-3
+4=+4
-1r = 1
Now divide
R= -1
