Guan Hui:

Sahimi:

Pls help !


Q1) Given that x2 + y2 = 185 and xy = -12, find the value of (x - y)2

Q2) If (a - b)2 = 72 and ab = 8.5, calculate the value of a2 + b2.

Q3) Given that 1043square - 1037square = 120y, find value the y without using calculator.

1)(x-y)^2=x^2-2xy+y^2
= x^2+y^2-2xy
= 185-2(-12)
=185+24
=209

2) you may want to try to do it using q1 method

3)using (x+y)(x-y)=x^2-y^2
1043^2-1037^2=(1043+1037)(1043-1037)
=(2080)(6)
=(208)(60)
=(104)(120)
=120y
therefore y= 104

thks v.m :lol:

Augmum:

Sahimi:

Hi pls help!


The two parallel sides of a trapezium are 3x and (5x + 8)cm each. Given the height between the parallel lines is (x - 1)cm. Show that the area is 4(x2 - 1).

hi
let me try to attempt yr question.

Area of trapezium = half the sum of parallel lines x height = ½ X (3x +5x+ 8 ) x (x-1)
=8x+8 / 2 X (x-1)
=2(4x + 4)/2 X (x-1)
=(4x + 4) (x-1)
= 4 (x+1) (x-1)
=4 (x2 –x+x-1)
=4 (x2-1) (Ans)

thks v.m

Pls help !


Q1) Given that x2 + y2 = 185 and xy = -12, find the value of (x - y)2

Q2) If (a - b)2 = 72 and ab = 8.5, calculate the value of a2 + b2.

Q3) Given that 1043square - 1037square = 120y, find value the y without using calculator.

Hi pls help!


The two parallel sides of a trapezium are 3x and (5x + 8)cm each. Given the height between the parallel lines is (x - 1)cm. Show that the area is 4(x2 - 1).

iFruit:

Sahimi:

Hi! pls help!!


If n is a number, show that for all values of n, (n3 + 11n) is divisible by 6. (sec Two maths)
Thks

n³ + 11n = n³ -n + 12n = n(n²-1)+12n = n(n-1)(n+1)+12n = (n-1)n(n+1)+12n


(n-1)n(n+1) is the product of 3 consecutive numbers which is always divisible by 6 ( you can use induction to prove if necessary) and 12n is divisible by 6.

So, n³ + 11n is divisible by 6

HTH

thks very much, iFruit.

Hi! pls help!!


If n is a number, show that for all values of n, (n3 + 11n) is divisible by 6. (sec Two maths)
Thks

acelancer:

Vaizard:

Hello, I am a candidate taking the PSLE.


What is the answer for the question about the flower wrapped with plastic bag? Is the answer B and anther? :shock:

yup! i put tht too! at first i was stump by it.....

I put that too! :celebrate:

yjmama:

My DD answered as water and oxygen

My ans is water and oxygen too! :celebrate:

eddie tan:

any body knows how to do the biceps and triceps Q which is in bkl A???so wats the ans for the kettle and snake Q? :? :?

My son's ans was P & R. Is it correct? :?

a) A : B+C+D

4 : 5

B : C+D
2 : 3


A : B : C : D
4 : 2 : 2 : 1

81 divide by 9 times 2 = 18
18/81 = 2/9

b) 1u = 81 divide by 9 = 9
9 times 4 = 36