## Lower Secondary Mathematics

### How to do this maths question?Any help is appreciated:)

Mr Tan’s monthly savings (S) is directly proportional to the square root of his monthly income (I). His income in January and February 2011 is $3600 and $2500 respectively. His savings in January is $80 more than in February. Find the amount he saved in January 2011.

### Re: How to do this maths question?Any help is appreciated:)

S ∝ √Ialbertong wrote:Mr Tan’s monthly savings (S) is directly proportional to the square root of his monthly income (I). His income in January and February 2011 is $3600 and $2500 respectively. His savings in January is $80 more than in February. Find the amount he saved in January 2011.

S=k√I

January's savings ,

S(J)=k√3600 =60k

February's savings,

S(F)=k√2500 =50k

His savings in January is $80 more than in February,

S(J) - S(F) = 80

60k - 50k = 80

10k = 80

k = 8

S = 8√I

S(J) = 8√3600 = 480

the amount he saved in January 2011 is

**$480**

- strawberrycupcakes
- OrangeBelt
**Posts:**61**Joined:**Mon Mar 11,

- Ovencookies
- OrangeBelt
**Posts:**43**Joined:**Tue Jul 02,**Total Likes:**1

### Re: How to do this maths question?Any help is appreciated:)

Hi my sons maths is quite weak what do your think is the best thing to do at this time when his o levels are coming soon ?

### Need help - Algebra Q

Algebra Q

Subtract 18x³ - 8x – 12 from 6x ( 2x² - 3)

My answer is different from the teacher, so need a third party (experts here) to prove me wrong.

Thanks.

Subtract 18x³ - 8x – 12 from 6x ( 2x² - 3)

My answer is different from the teacher, so need a third party (experts here) to prove me wrong.

Thanks.

### Re: Need help - Algebra Q

6x ( 2x² - 3 ) - ( 18x³ - 8x – 12 )

= ( 12x³ - 18x ) - ( 18x³ - 8x – 12 )

= 12x³ - 18x - 18x³ + 8x + 12

= - 6x³ - 10x + 12

Is the answer same as yours or your teacher's?

= ( 12x³ - 18x ) - ( 18x³ - 8x – 12 )

= 12x³ - 18x - 18x³ + 8x + 12

= - 6x³ - 10x + 12

Is the answer same as yours or your teacher's?

- Michaelia0816
- BrownBelt
**Posts:**701**Joined:**Wed Feb 29,

### Q&A - Math

Need help with coordinate question:

Diagram:

http://t.co/6BaWYM3Fka

Questions:

(a) The coordinates of A and B are ____ and ____ respectively.

(c) The area of Triangle BOC is ____ units

(d) AB cuts the line x = 0 at ____.

(f) The line AB passes through (p,-1), the value of p is ___.

Diagram:

http://t.co/6BaWYM3Fka

Questions:

(a) The coordinates of A and B are ____ and ____ respectively.

(c) The area of Triangle BOC is ____ units

(d) AB cuts the line x = 0 at ____.

(f) The line AB passes through (p,-1), the value of p is ___.