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Factor Review. Algebra B. Multiplying. a ( b + c ). ab + ac. Factoring. Factoring expressions. Factoring an expression is the opposite of multiplying. Often: When we multiply an expression we remove the parentheses.
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Factor Review Algebra B
Multiplying a(b + c) ab + ac Factoring Factoring expressions Factoring an expression is the opposite of multiplying. Often: When we multiply an expression we remove the parentheses. When we factor an expression we write it with parentheses.
a2 + 3a + 2 Factoring Factoring expressions Factoring an expression is the opposite of multiplying. Multiplying (a + 1)(a + 2) Often: When we multiply an expression we remove the parentheses. When we factor an expression we write it with parentheses.
Then, look at the remaining factor. • If it is Linear, you are done factoring.
Then, look at the remaining factor. Difference of Squares a2 – b2 = (a-b)(a+b) Is it Quadratic? If it is a: yes Trinomial Calculate the discriminant b2 – 4ac. Is it square? yes Trinomial where a = 1 Find factors of c that add to b. yes no Trinomial where a 1 Find factors of ac that add to b. Split the middle term and then factor by grouping. Can’t be factored more
Remember: • First factor out GCF if there is one • Remember: Multiply to last term add to middle. • ax2+bx+c=( + )( + )ax2-bx+c = ( - )( - )ax2bx-c = ( + )( - ) • If you are using split the middle, split the linear term into two linear terms
Or Split the Middle Term: Steps Factor out GCF if there is one. Identify abc Multiply ac Find factors of (ac) that add up to b Split bx into two terms Factor by grouping
Factoring trinomials of form: Splitting the middle term Steps Factor out GCF if there is one. Identify abc Multiply ac Find factors of (ac) that add up to b Split bx into two terms Factor by grouping No GCF a=6b=-5c=-4 ac = 6(-4)=-24 -8 and 3 Which factors of -24 add up to -5?
Or Another way to split the middle • Factor 2x2 + x - 6 • Multiply a and c together. 2∙(-6) = -12 • Find factors of ac that add up to b. -3 and 4 • Fill in a box as shown:
2x -3 • Factor 2x2 + x – 6 • Factor out the common factor from the top row and place it beside the box next to the first term. • Factor out the common factor from the bottom row and place it beside the box next to the “other factor.” • Factor out the common factor from the left column and place it on top of the box above the first term. • Factor out the common factor from the right column and place it on top of the box above the “one factor.” • Put together your answer. x +2 (x+2)(2x-3)
Is it Cubic or a higher degree 4-Term Polynomial Try to factor by grouping. If it is a: yes
Factoring by grouping Factor a3+ a2+ 4a + 4 Two terms share a common factor of a2and the remaining two terms share a common factor of 4. a3 + a2+ 4a + 4 =a3 + a2+ 4a+ 4 = a2(a+ 1) + 4(a+ 1) a2(a + 1) and+ 4(a + 1)share a common factor of (a + 1) so we can write this as (a + 1)(a2+ 4)