BIT Problem Sheet I BIT Problem Sheet I

Question 1
Perform the following calculations
(i) (7)+(-14)(ii)(-8)+(9)
(iii)(-4)-(13) (iv)(-5)-(-17)
(v)(-9)×(11) (vi)(-11)×(-11)
(vii)(-32)¸(8) (viii)(-12)¸(-6)

Question 2
Simplify the following algebraic inequalities
(i) 5 < 2x +15 (ii) x-25 > 7
(iii) 7x + 12 < 12x -3 (iv) -9x -17 > 9x +1
(v) 3x -29 < 7x+11 (vi) -11x -12 < 19x +8

Question 3
Show, step, by step, how the expression on the left-hand side simplifies to that on the right.
(i) 3x+4x+7(2x-3) = 21x-21
(ii)4x2 + 7x+2x(4x-5) = 12x2 - 3x
(iii) 2x(y+2) - 2y(x+2) = 4x-4y
(iv) (x+2)(y-2) +(x-3)(y+2) = 2xy -y -10
(v) (x+2)(x+2) - (x-2)(x-2) = 8x
(vi) (x+2)(x+2) - x(x+2) = 2x+4

Question 4
Perform the following calculations:
(i) (2/3) (5/7) (ii) (-2/3) (7/5)
(iii) (3) (2/5) (iv) (6/7) ([9/ 13])
(v) (2/3) ¸([5/ 11]) (vi) (5) ¸(-3/4)
(vii) (7/3) ¸(8) (viii) (-2/3) ¸(1/5)

Question 5
Show, step, by step, how the expression on the left-hand side simplifies to that on the right. Use cancellation where possible.
(i)

1
7
+ 2
3
= 17
21
(ii)
7
8
+ 3
4
= 1 5
8
(iii)
1
3
+ 3
5
+ 5
7
= 1 68
105
(iv)
1
9
- 2
3
= - 5
9
(v)
3
8
- 5
56
= 2
7
(vi)
2
7
+ 2
3
- 13
21
= 1
3
(vii)
3
11
- 7
9
- 1
7
= - 449
693

Question 6
Show, step, by step, how the expression on the left-hand side simplifies to that on the right.
(i)

x
2
- x
3
= x
6
(ii)
2 æ
ç
è
2
x
- x
2
ö
÷
ø
= 4-x2
x
(iii)
- 12
P
æ
ç
è
3P
2
+ P
2
ö
÷
ø
= -24
(iv)
æ
ç
è
3
x
ö
÷
ø

x+3
= x
x2 + 3x
(v)
æ
ç
è
5Q
P+2
ö
÷
ø

1
P+2
= 5Q
(vi)
(1+t2)(1+t2)
(1-t2)(1-t2)
- (2t)(2t)
(1-t2)(1-t2)
= 1
(vii)
x+ 2x
x-2

1+ 4
x2-4
= x+2

Question 7
Given the following lines:
(i)y = x+2
(ii)y = -4x+3
(iii)y = 0.5x -2
(iv)2y = 6x +4

(a) Write down the slope, x intercept and yintercept for each line.
(b) Calculate the values of y when x = -2,0,2,4,6.
(c) Plot each line over the interval x = -2 to x = 6.

Question 8
Write each of the following in slope intercept form:
(i)2y-5x+10 = 0 (ii)0.2y +0.4x = 2
(iii)2x+3y-1 = 0 (iv)4x+3y-2 = 0

Question 9
Find the equation of each line described by the following:
(i)Slope = 2, y-intercept = 0(ii)Slope = -2, y-intercept = 0
(iii)Slope = 1, y-intercept = -2(iv)Slope = -1, y-intercept = 2

Question 10
In each case, find if the two lines given intersect, and if so find the point (or points) of intersection:
(i)2x+y = 5 5x+4y = 11
(ii) x-5y = 11 3x-y = 5
(iii)3x+2y = 6 6x+4y = 12
(iv)x+7 = y 2x-3y+18 = 0

(v)3x-7y = 12 5x-2y = 20
(vi)3x-2y = 5 2x+5y = 12
(vii)3x+2y = 11 2x+1 = 0
(viii) x-3y = 5 2x-6y = 3

Question 11
Find the equation of the line joining the following points:
(i)(2,3)(1,7)
(ii)(-2,1)(1,6)
(iii)(0,-4)(-2,-5)
(iv)(-1,4)(-2,-1)
(v)(0,4)(-1,5)
(vi)(2,0)(0,-4)

Answers

Question 1
(i) -7 (ii) 1 (iii) -17 (iv) 12
(v) -99 (vi) 121 (vii) -4 (viii) 2

Question 2
(i) -5 < x (ii) x > 32 (iii) 3 < x (iv) -1 > x
(v) -10 < x (vi) -2/3 < x

Question 4
(i) [10/ 21] (ii) - [14/ 15] (iii) 6/5 = 11/5 (iv) [54/ 91]
(v) [22/ 15] = 1[7/ 15] (vi) -[20/ 3] = -62/3 (vii) [7/ 24] (viii) -[10/ 3] = - 31/3

Question 7
(i) Slope = 1, Intercepts: (0,2), (-2, 0); Points:(-2,0),(0,2),(2,4),(4,6),(6,8).
(ii) Slope = -4, Intercepts: (0,3),(3/4,0); Points:(-2,11),(0,3),(2,-5),(4,-13),
(6,-21).
(iii) Slope = -1/2, Intercepts: (0,-2), (4, 0); Points:(-2,-3),(0,-2),(2,-1), (4,0),(6,1).
(iv) Slope = 3, Intercepts: (0,2), (-2/3, 0); Points:(-2,-4),(0,2),(2,8),(4,14),(6,20).

Question 8
(i) y = 5/2 x -5 (ii)y = -2 x +10
(iii)y = - 2/3 x +1/3(iv)y = -11/3 x +2/3

Question 9
(i)y = 2x (ii)y = -2x
(iii)y = x-2 (iv)y = -x+2

Question 10
(i)(3,-1)
(ii)(1,-2)
(iii)lines are the same, an infinite number of solutions exist.
(iv) (-3,4)
(v) (4,0)
(vi) ([49/ 19], [26/ 19])
(vii)(-1/2, 61/4)
(viii)lines are parallel, no solution exists

Question 11
(i) y = -4x+11
(ii) y = 12/3x + 41/3
(iii)y = 1/2 x -4
(iv) y = 5x+9
(v) y = -x+4
(vi)y = 2x-4


File translated from TEX by TTH, version 2.10.
On 6 May 1999, 15:37.