We use quadratic formula then
For a expression
The quadratic formula is

If underroot values becomes negative we use iota(i)
which has value=√-1
OK the question is asking what happens when you subtract (1.9+2.2) from 1.9x2.2 or more clearly 1.9x2.2-(1.9+2.2) which equals 4.18-4.1 or .08
1 yogurt = 45p
1p = ? yogurt
1 ÷ 45 = 0.02
5 × 0.02 = 0.10
0.10 yogurt can be bought with 5p (pounds)
Answer:
C the 3 one is the answer