Answer:
(2z+5) (2z-3)
Step-by-step explanation:
First, multiply the first coefficient by the third.
4*-15=-60
Then find factors of -60 that add up to the middle term.
The factors are: -6 and 10-------> -6*10=-60 and -6+10=4 so -6 and 10 are the correct factors.
Break up the middle term with the factors that you got above. The new equation will be: 4-6z+10z-15
Factor by grouping.
First, break the equation into two
(4-6z) (10z-15)
Then, factor out the greatest number you can
2z(2z-3) 5(2z-3)
You are then left with a common binomial of 2z-3. COmbine the common binomial into 1 and combine the 2 numbers you factored out in the step above (2z and 5) The final equation will be this:
(2z+5) (2z-3)