[HBL Class Discussion] Solving Equations - WORD Problems (p19, Q3)

 

Linear Equations [HW1] (Part 2) Articulating the solving of Equations

Refer to the Google Classroom for the complete set of instructions for HW1.

This is Part (2) of HW1

Pay attention to he following when you articulate the solving of the equation:

The marking rubrics

(A) Clarity in presentation of working (max: 2m)
[0] Does not solve equation systematically (e.g. change to arithmetic calculation halfway)
[1] Presentation issues (e.g. 2 "=" on the same line)
[2] Clear and systematic presentation

(B) Answer (max: 1m)
[0] Incorrect answer or when non-exact answer is presented
[1] Correct answer - found through equation solving

(C) Articulation of Concepts (max: 2m)
[0] Balancing concepts not articulated at all
[1] Some appropriate terms are used to describe the balancing concept OR Some appropriate algebraic manipulation terms like "single fraction", "simplify", "expand" are used
[2] Most appropriate terms are used to explain concepts and manipulation

(D) The Product (max: 1m)
[0] Video is beyond 2 minutes. Quality is poor (e.g. voice not audible, what's written is not clearly capture)
[1] Video is kept to 2 minutes (max) with audible voice

Solving Equations (Study Notes)

As discussed during lesson today

Algebra: Equation vs Expression

(I) Algebraic Expressions vs Equations
The following are expressions

• 3x
• 5 - 2y
• p + 2q - 45
• mn

The following are equations:

• 2x = 4
• x + 8 = 20
• x² = 36
• 2x + y = 4

Can you tell the difference between an expression and an equation?

(II) Coefficients, Variables and Constants
In the following algebraic expressions:

(a) 6x

• x is a variable
• 6 is the coefficient of x
• There is no constant

(b) 2y + 5

• y is a variable
• 2 is the coefficient of y
• 5 is the constant

(c) 3m + 7n + 9

• m and n are variables
• 3 and 7 are coefficients of m and n respectively
• 9 is the constant

(d) p + 2q - 45

• p and q are variables
• 1 and 2 are coefficients of p and q respectively
• -45 is the constant

(e) 5a - 3b + 1

• a and b are variables
• 5 and -3 are coefficients of a and b respectively
• 1 is the constant

(f) x - y

• x and y are variables
• 1 and -1 are coefficients of x and y respectively
• There is no constant

When given an expression, are you able to pick out the variable(s), coefficient(s) and constant terms?
Click HERE to read more about these...

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Algebra: Equation vs Expression

(I) Algebraic Expressions vs Equations
The following are expressions

• 3x
• 5 - 2y
• p + 2q - 45
• mn

The following are equations:

• 2x = 4
• x + 8 = 20
• x² = 36
• 2x + y = 4

Can you tell the difference between an expression and an equation?

(II) Coefficients, Variables and Constants
In the following algebraic expressions:

(a) 6x

• x is a variable
• 6 is the coefficient of x
• There is no constant

(b) 2y + 5

• y is a variable
• 2 is the coefficient of y
• 5 is the constant

(c) 3m + 7n + 9

• m and n are variables
• 3 and 7 are coefficients of m and n respectively
• 9 is the constant

(d) p + 2q - 45

• p and q are variables
• 1 and 2 are coefficients of p and q respectively
• -45 is the constant

(e) 5a - 3b + 1

• a and b are variables
• 5 and -3 are coefficients of a and b respectively
• 1 is the constant

(f) x - y

• x and y are variables
• 1 and -1 are coefficients of x and y respectively
• There is no constant

When given an expression, are you able to pick out the variable(s), coefficient(s) and constant terms?
Click HERE to read more about these...

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