How do you factor the trinomial #4 a^2-a - 5#?

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Answer 1 · 2018-07-17T04:20:15

#(a+1)(4a-5)#

This is in standard form, or #ax^2 + bx + c#, where #a = 4#, #b = -1#, and #c = -5#.

To factor this, we first have to find #2# numbers that:

These two numbers are #-5# and #4#.

With these numbers, we can rewrite the trinomial like this:
#4a^2 - 5a + 4a - 5#

Now we factor by grouping:
#(4a^2 - 5a) + (4a - 5)#

#=a(4a - 5) + 1(4a-5)#

#=(a+1)(4a-5)#

Hope this helps!