how does 1/20 + 1/15 equal 8.57

Question

lgbasallote · Answer

60 is the LCD..

(4 + 3)/60 = 7/60 = 0.1166

should be that...

anonymous · Answer

well... I think they're not equal
$$\LARGE \frac{1}{20}+\frac{1}{15}=8\frac{57}{100}$$
$$\LARGE \frac{3}{60}+\frac{4}{60}=\frac{800}{100}+\frac{57}{100}$$
$$\LARGE \frac{7}{60}=\frac{857}{100}$$

they're not equal !

anonymous · Answer

http://pages.uoregon.edu/dparks/206/resistorvoltage/

anonymous · Answer

can u guys try and figure out what this guy did pls

anonymous · Answer

which task ?

anonymous · Answer

and that's not math, that's physic !

lgbasallote · Answer

it's 1/R lol..you take the reciprocal :p

lgbasallote · Answer

1/R = 7/60

R = 60/7
R = what you said

anonymous · Answer

1/Ra=1/20+1/15
Ra=8.57Ω

this one??  :B

anonymous · Answer

yea that one

anonymous · Answer

$$\LARGE \frac{1}{Ra}=\frac{1}{20}+\frac{1}{15}$$
$$\LARGE \frac{1}{Ra}=\frac{7}{60}$$
$$\LARGE 60=7\cdot Ra \quad \quad \Longrightarrow Ra=\frac{60}{7}$$

Ra=8.571428...

anonymous · Answer

lol i see

anonymous · Answer

ok