Maths Basic Algebra Sec 2 Level

---Max--- SG

Would anyone be kind to answer this question?

Mrs Rani spend $96 on some caps and t shirts for her children. A cap and a T-shirt cost $14.

If she spends all her money on buying caps, she can buy 4 more caps than if she spends all her money on T -shirt.

bi) Write down an expression in terms of x and show that it reduces to x^2 + 34x - 336 = 0

I don't understand the sentence in bold could any readers enlighten me? If possible some working would be nice.

dkcx SG

Thats more like how you should behave.

The statement just ask you to form that equation using x and once formed, reduce it to the given equation.

I will give u a clue, please try and ask again if you still cannot solve this.

1) Form equations in terms of x and y using x for cost of t-shirt and y for cost of cap.

2) You will get 2 equations which you can use simultaneous equations to combine into 1

3) Simplify and you will get your answer.

Mr.ms.chairperson SG

haha ok this question is a bit tricky. At first glance it looks like you don't have enough information to solve the question.

1) let x and y be the price of t-shirt and cap respectively.

2)eh?! you don't have anymore information to make any equation with using only x and y. How? So what you do is you let z be the number of shirts you can buy with $96. then you can form another equation. (i.e z*x=96). you can form another equation using the information for the cap.

3) you have then 3 simulataneous equations and 3 unknowns(x,y,z). Through some impressive mathematics manipulation, you can reduce to get the equation in bold. =)

SBS261P SG

Mr.ms.chairperson, don't need a z to solve the question.

you can use 96/x = 96/y + 4

after all, it IS sec 2 algebra...

weiwei SG

very long since i log in to help. is spoon-feeding allowed?

sec 2 algebra i think only deals with only one variable (correct me if i'm outdated):

let the price of a tshirt be $x.

so the price of a cap will be $(14-x).

96/x + 4 = 96/(14-x) <--- equating the number of items that can be bought

simplifying the above (dont spoonfeed all the way), you will get:

4x^2 + 136x - 1344 = 0

divide by 4 throughout,

x^2 + 34x - 336 = 0 (reducing to this equation means how u get to this equation using the information provided by the question to form an equation and simplify)

solving, x = 8 or -42(rejected, how can price of tshirt be negative)

hence price of tshirt = $8, price of cap = $6

happy studying!

Lokey SG

There are many ways of solving it.

C + T = 14

Since she can buy 4 more C than T,

(common sense Cap is cheap, T shirt more expensive, it is true that in real life T-shirt is more expensive then cap. People who came out with question is living in real world!!)

then 96/C - 96/T = 4

Sub (C= 14-T),

96/(14-T) -96/T = 4

divide by 4

24/(14-T) - 24/T = 1

24T - 366 + 24T = 14T - T^2

T^2 + 34T -366 = 0 (if cant think straight, you can back calculate this)

(T-8)(T+42)=0

T= 8 or -42 (rejected)

C= 6

Countercheck

96/(6) -96/8 = 4

---------------------------------------------

Lazy man working (not of EXAM) my REAL CALCULATION

No of cap - no of shirt = 4

96/Cap -96/Shirt = 4

divide by 4

24/Cap - 24/Shirt = 1

1 x 24 = 24

2 x 12 = 24

3 x 8 = 24

4 x 6 = 24

Ans: Cap is 6, Shirt is 8, as only this 2 value can fit the equation. I dont even you to tell me that Cap + Shirt = 14

So and spend more time shopping, mugging at home doing maths does not help you in thinking. Maths is created by human it is part of life. Just have combine real life with virtual thinking maths is no that hard.

Lokey SG

very long since i log in to help. is spoon-feeding allowed?

sec 2 algebra i think only deals with only one variable (correct me if i'm outdated):

let the price of a cap be $x.

so the price of a tshirt will be $(14-x).

96/x + 4 = 96/(14-x) <--- equating the number of items that can be bought

simplifying the above (dont spoonfeed all the way), you will get:

4x^2 + 136x - 1344 = 0

divide by 4 throughout,

x^2 + 34x - 336 = 0 (reducing to this equation means how u get to this equation using the information provided by the question to form an equation and simplify)

solving, x = 8 or -42(rejected, how can price of cap be negative)

hence price of cap = $8, price of tshirt = $6

happy studying!

Am I right? I can buy more Cap than T-shirt, so T-Shirt is more expensive, how can it be $6!!!???

Forbiddensinner SG

Yes you are correct. Logically speaking the item which you can buy more of should be cheaper. 0o

weiwei SG

Am I right? I can buy more Cap than T-shirt, so T-Shirt is more expensive, how can it be $6!!!???

opps. i put the 4 more caps, the +4 should be -4. sorry. i shall edit it.