Mathematics
Grade 9
15 min
Divide by 4
Divide by 4
Tutorial Preview
1
Introduction & Learning Objectives
Learning Objectives
Apply division by 4 to factor polynomials with a common factor.
Use division by 4 as the first step in solving quadratic equations by completing the square.
Simplify radical expressions by identifying and factoring out perfect squares, specifically 4 and its multiples.
Analyze and describe horizontal transformations of functions involving a factor of 4.
Efficiently find the vertex of a parabola when the 'a' coefficient is 4.
Manipulate polynomial expressions and equations by dividing every term by 4 to simplify the problem.
Ever feel like a complex algebra problem is just a simple one in disguise? What if the secret to solving `4x² + 24x - 16 = 0` was as easy as dividing by 4? 🤔
This tutorial goes beyond basic arithmetic. We will explore how t...
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Key Concepts & Vocabulary
TermDefinitionExample
Greatest Common Factor (GCF)The largest number and/or variable that divides into each term of a polynomial expression without a remainder.In the polynomial `4x² + 8x - 12`, the GCF is 4. Dividing the polynomial by 4 gives `4(x² + 2x - 3)`.
Quadratic Equation in Standard FormAn equation of the form `ax² + bx + c = 0`, where 'a', 'b', and 'c' are constants and 'a' is not equal to 0.`4x² + 16x + 8 = 0` is a quadratic equation where a=4, b=16, and c=8. Dividing by 4 simplifies it to `x² + 4x + 2 = 0`.
RadicandThe number or expression inside a radical symbol (√).In the expression `√48`, the radicand is 48. To simplify, we can factor it as `√(16 * 3)`. Since 16 is `4²`, we can see the connection to 4.
Perfect Square TrinomialA trinom...
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Core Formulas
The Division Property of Equality
If `A = B` and `C ≠ 0`, then `A/C = B/C`.
This fundamental rule allows you to divide both sides of an equation by the same non-zero number. We use this to simplify entire quadratic or polynomial equations by dividing every single term by 4.
Factoring out the GCF
`4ax + 4b = 4(ax + b)`
When every term in an expression shares a common factor of 4, you can 'factor it out'. This is equivalent to dividing each term by 4 and placing the result in parentheses with the 4 outside.
Simplifying Radicals
`√(4a) = √4 * √a = 2√a`
If the radicand has a factor that is a perfect square (like 4), you can split the radical into two and simplify the perfect square part. This is a key step in simplifying radical expressions.
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Challenging
The graph of `f(x) = x²` is transformed to `g(x) = 4f(x+1) - 8`. If this new function `g(x)` is then transformed by a horizontal compression by a factor of 1/4, what is the vertex of the final resulting parabola?
A.(-1/4, -8)
B.(-4, -8)
C.(-1, -32)
D.(-1, -2)
Challenging
Solve the radical equation `√(16x + 32) = 4x`.
A.x = 2 only
B.x = -1 only
C.x = 2 and x = -1
D.No real solution
Challenging
Consider the quadratic equation `ax² + bx + c = 0` with roots `r₁` and `r₂`. Now consider a new equation `4ax² + 4bx + 4c = 0`. What are the roots of this new equation?
A.4r₁ and 4r₂
B.r₁/4 and r₂/4
C.r₁ and r₂
D.r₁ + 4 and r₂ + 4
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