FACTORING BY GROUPING Factoring by Grouping These kind
FACTORING BY GROUPING
Factoring by Grouping • These kind of problems are really fun - pretend they’re in the Sunday puzzler. • These problems usually have four terms. • Remember G. C. F. means greatest common factor.
Divide and conquer • Factor: • Factor the G. C. F. out of the first two terms:
Hippity-hop & make a slot CHEAT! Copy the (x + 2 y )
Fill the Slot Just focus on the +7 x What needs to go in the slot to make +7 x?
Fill the Slot
Check your ‘cheat’ Now distribute the +7 to make sure we get the original last two terms. This ensures that we didn’t shoot ourselves in the foot by ‘cheating’
Build a house for the leftovers Pull out the common factor; build a house for the leftovers!
Check your work Foil to check your work.
Sometimes you need to rearrange Factor 5 x 2 - 14 y - 10 xy + 7 x You can’t factor the first 2! Rewrite: 5 x 2 - 10 xy + 7 x - 14 y Be careful to move the sign with the numbers. Moving a number without his sign is like chopping off his arm!
Remember When you pull a term out in front of the parentheses you want to be sure: It is a factor of each original term. It’s the GREATEST common factor of the terms.
Watch those signs! Factor:
WHENEVER YOU FACTOR ALWAYS pull out the greatest common factor G. C. F. FIRST! The End
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