Ask Singapore Homework?

Upload a photo of a Singapore homework and someone will email you the solution for free.



Question

secondary 3 | E Maths
One Answer Below

Anyone can contribute an answer, even non-tutors.

Answer This Question
kay
Kay

secondary 3 chevron_right E Maths

Need detailed workings !

Date Posted: 5 years ago
Views: 392
snell
Snell
5 years ago
V=240 is constant,
V=IR
240=IR [1]

240=(I+1)(R-20)
240=IR-20I+R-20
Subst. [1]
240=240-20I+R-20
R - 20I=20 [2]

Subst. [1] into [2],
R - 4800/R = 20
R² - 20R - 4800 = 0
R=80 or R=-60(n.a.)

See 1 Answer

done {{ upvoteCount }} Upvotes
clear {{ downvoteCount * -1 }} Downvotes
Chong Ten San
Chong Ten San's answer
563 answers (Tutor Details)
1st
Clear?