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Patterns and Algebra - Simplifying Algebraic Expressions

Grade 6IB

Review the key concepts, formulae, and examples before starting your quiz.

๐Ÿ”‘Concepts

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An algebraic expression is a mathematical phrase that can contain ordinary numbers, variables (like xx or yy), and operators (like ++, โˆ’-, ร—\times, and รท\div). Visually, you can imagine variables as empty boxes or containers where different numbers can be placed.

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A term is a single part of an expression separated by plus or minus signs. For example, in the expression 5x+3yโˆ’75x + 3y - 7, there are three terms: 5x5x, 3y3y, and โˆ’7-7. A constant is a term that is just a number without a variable.

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The coefficient is the numerical factor of a term containing a variable. In the term 4x4x, the number 44 is the coefficient. If a variable appears alone, like zz, its coefficient is understood to be 11.

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Like terms are terms that have the exact same variable parts raised to the same power. Visually, you can think of like terms as items of the same category, such as apples and oranges; you can add 33 apples and 22 apples to get 55 apples, but you cannot combine 33 apples and 22 oranges.

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Simplifying an expression involves combining like terms by adding or subtracting their coefficients. For example, 5a+2a5a + 2a simplifies to 7a7a. Visualizing this on a number line can help when dealing with negative coefficients, such as 4xโˆ’6x=โˆ’2x4x - 6x = -2x.

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The Distributive Property allows you to remove parentheses by multiplying the term outside the bracket by every term inside. It is written as a(b+c)=ab+aca(b + c) = ab + ac. Visually, imagine drawing arrows from the outside term to each term inside the parentheses to ensure nothing is missed.

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When simplifying complex expressions, follow the order of operations (BODMAS/PEMDAS). This means dealing with Brackets first, then multiplication/division from left to right, and finally addition/subtraction from left to right.

๐Ÿ“Formulae

a(b+c)=ab+aca(b + c) = ab + ac

a(bโˆ’c)=abโˆ’aca(b - c) = ab - ac

x+x=2xx + x = 2x

xร—x=x2x \times x = x^2

ax+bx=(a+b)xax + bx = (a + b)x

๐Ÿ’กExamples

Problem 1:

Simplify the expression: 7x+5โˆ’3x+87x + 5 - 3x + 8

Solution:

Step 1: Identify the like terms. The terms with xx are 7x7x and โˆ’3x-3x. The constant terms are +5+5 and +8+8. Step 2: Group the like terms together: (7xโˆ’3x)+(5+8)(7x - 3x) + (5 + 8). Step 3: Combine the coefficients of the variable terms: 7โˆ’3=47 - 3 = 4, so 7xโˆ’3x=4x7x - 3x = 4x. Step 4: Add the constant terms: 5+8=135 + 8 = 13. Step 5: Write the simplified expression: 4x+134x + 13.

Explanation:

To simplify, we group the variable terms together and the constant terms together, then perform the addition or subtraction for each group separately.

Problem 2:

Simplify the expression: 4(2yโˆ’3)+5y4(2y - 3) + 5y

Solution:

Step 1: Use the distributive property to remove the brackets: 4ร—2y4 \times 2y and 4ร—(โˆ’3)4 \times (-3). 4(2yโˆ’3)=8yโˆ’124(2y - 3) = 8y - 12. Step 2: Rewrite the expression with the expanded terms: 8yโˆ’12+5y8y - 12 + 5y. Step 3: Identify and group like terms: (8y+5y)โˆ’12(8y + 5y) - 12. Step 4: Combine the yy terms: 8+5=138 + 5 = 13, so 8y+5y=13y8y + 5y = 13y. Step 5: The final simplified expression is 13yโˆ’1213y - 12.

Explanation:

First, expand the brackets by multiplying the coefficient outside by every term inside. Then, combine the resulting like terms to find the simplest form.