Domain of f = R .............
Find a common denominator which is 12
1*3=3 4*3=12 so 3 3/12
then 5*2=10 6*2=12 so 2 10/12
2 10/12+3 3/12= 5 13/12
13/12= 1 1/12 plus 5= 6 1/12
so your answer would be 6 1/12
2x² + 3x -8 = 0
a = 2 , b = 3 , c = -8
So..
D = b²-4ac = 9 + 64 = 73
for bigger solution , use x = -b + √D / 2a
For smaller solution, use x = -b - √D / 2a
So
= -3 + √73 / 2. 2
= 1/4 (√73 -3)
Hopefully helpfull.. ^_^