DSC1520 EXAM PACK 2023
200+ QUESTIONS AND CORRECT
ANSWERS LATEST UPDATE.
Study Unit 1 : Mathematical preliminaries
Chapter 1 : Sections 1.1 – 1.6
1. Basics
• Numbers: different type of numbers – Natural, Real, etc.
Also called constants
• Basic operations
o + (add); 2 + 3 = 5
o �...
Study Unit 1 : Mathematical preliminaries
Chapter 1 : Sections 1.1 – 1.6
1. Basics
• Numbers: different type of numbers – Natural, Real, etc.
Also called constants
• Basic operations
o + (add); 2 + 3 = 5
o – (subtract); 3 – 2 = 1
o x (multiply); also •; 3 x 2 = 3•2 = 6
o ÷ (division) also / or fraction ( 1 = 1 divide by 2);
2
6
6 ÷ 3 = 6/3 = =2
3
Remember:
1 x anything = anything
1x8=8
g
0 x anything = 0
0x4=0
1 + anything = one more than anything
1 + 345 = 346
0 + anything = anything
0 + 34 = 34
anything ÷ 0 = not allowed
12 ÷ 0 = not allowed
0 ÷ anything = 0
0÷7=0
, Page 2 of 167
• Brackets ( ) : group operations together
(3 + 4) – 3
=7–3
=4
• Order of operation: BODMAS
Brackets; Of; Divide; Multiply; Add; Subtract
40 – 4 x (5 + 8) + 20
= 40 – 4 x (13) + 20
= 40 – 52 + 20
=8
• Variables: used for unknown or generalisation of things: place
holder: use alphabetic characters for example X or A or Y. Can
take on different values
3x + 2y +7g + x
3x is known as a term with coefficient 3 and variable x
g
Remember : the last term x has a coefficient value of 1 in front of
it namely 1x
o Operations on variables or unknown:
 + and – : only if same variable, then + or – coefficients and
variable stays the same
3x + 4x + 3 = (3 + 4)x + 3 = 7x + 3
5x – x – 6 = (5 – 1)x – 6 = 4x –6
, Page 3 of 167
 x and ÷ : only if same variable, then x and ÷ coefficient
and unknowns
3a x 4a = (3x4) (a x a) = 12a 2
2 x2 xx
2x ÷ x = (2÷1) = 2 = 2x
x x
• Laws of operations
o Commutative law : order
 a+b=b+a 3+4=4+3=7
 axb=bxa 3 × 4 = 4 × 3 = 12
 a–b ≠b–a 4–3=1 ≠3 – 4 = –1
 a÷b ≠b ÷ a 4÷2=2 ≠2 ÷ 4 = 0,5
o Associative law: ( )
 (a + b) + c = a + (b + c)
(3 + 4) + 2 = 7 + 2 = 9
3 + (4 + 2) = 3 + 6 = 9
g
 (a x b) x c = a x (b x c)
(3 × 4) ×2 = 12 × 2 = 24
3 × (4 × 2) = 3 × 8 = 24
 (a – b) – c ≠a – (b – c)
(3 – 4) – 2 = –1 – 2 = –3
3 – (4 – 2) = 3 – 2 = 1
 (a ÷ b) ÷ c ≠a ÷ (b ÷ c)
(12 ÷ 2) ÷ 2 = 6 ÷ 2 = 3
12 ÷ (2 ÷ 2) = 12 ÷ 1 = 12
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller Tutor23. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for £2.78. You're not tied to anything after your purchase.