S2 Maths Questions

2009-11-04 11:26 pm

Please help me to solve the following question:

1) Given that the graph of the equation 2X - 5y = a intersects the
x-axis at A(5,0) and the y-axis at B(0,b),

(a) find the value of a,
(b) use the result of (a) to find the value of b.

2) Simplify the following algebraic fractions
ab+bc+cd+ad over ab+bc-cd-ad

3) Draw the graph of the linear equation 5-1/2y=x, where x lies between-3
and 6

{scale for x-axis: 10 divisions (1cm) =1 unit
scale for y-axis: 10 divisions (1cm) =2 units}

Use the graph drawn in (a) to answer the following questions.
i) Does the point A(4,2) lie on the line?
ii) If B(b,0) is a point on the line, what is the value of b?
iii) If C(0,c) is a point on the line, what is the value of c?
iv) If D(d,4) is a point on the line, what is the value of d?

回答 (1)

[匿名]

2009-11-05 12:23 am

✔ 最佳答案

1)
a)
Put (5 , 0) into 2x - 5y = a
10 - 0 = a
a = 10
b)
2x - 5y = 10
Put (0 ,b) into the equ.
- 5b = 10
b = - 2

2)
(ab + bc + cd + ad) / (ab + bc - cd - ad)
= [(a + c)b + (a + c)d] / [(a + c)b - (a + c)d]
= (a + c)(b + d) / (a + c)(b - d)
= (b + d) / (b - d)

3)
i)
Put (4 , 2) into 5-1/2y=x
5 - (1 / 2) * 2 = 4
5 - 1 = 4
So, (4 , 2) lies on the line.

ii)
put (b , 0) into the equ.
5 - (1 / 2) * 0 = b
b = 5

iii)
put (0 , c) into the equ.
5 - (1 / 2) * c = 0
5 = c / 2
c = 10

iv)
put (d , 4) into the equ.
5 - (1 / 2) * 4 = d
5 - 2 = d
d = 3

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