Answer:
r = 1.6
Step-by-step explanation:
given r varies directly with m² and inversely as n then the equation relating them is
r = [tex]\frac{km^2}{n}[/tex] ← k is the constant of variation
to find k use the condition r = 18 when m = 6 and n = 4 , then
18 = [tex]\frac{k(6)^2}{4}[/tex] = [tex]\frac{36k}{4}[/tex] ( multiply both sides by 4 to clear the fraction )
72 = 36k ( divide both sides by 36 )
2 = k
r = [tex]\frac{2m^2}{n}[/tex] ← equation of variation
when m = 2 and n = 5 , then
r = [tex]\frac{2(2)^2}{5}[/tex] = [tex]\frac{2(4)}{5}[/tex] = [tex]\frac{8}{5}[/tex] = 1.6
