20 POINTS WILL MARK BRAINLIEST plz help me very simple

Answer:
£ 2.38
Step-by-step explanation:
Cost of 2.5 kg potatoes = £ 1.40
Cost of 1 kg potatoes = [tex]\frac{1.40}{2.5}\\[/tex]
Cost of 4.25 kg potatoes = [tex]\frac{1.40}{2.5}*4.25\\\\[/tex]
= 1.40 * 1.7
= £ 2.38