15z² - (3z - 1) (4z - 1) + 1
In a calculation like this, are you supposed to change the minus inside both parantheses to plus?
+37158 Your question does not say that the expression = 0 , so
15z^2 + (-1)(3z-1)(4z-1) + 1 you can change to -3z+1 or -4z+1 but NOT BOTH (or just leave it)
15 z^2 + (-1)(12z^2 - 7z +1) +1
15z^2 -12z+7z-1+1
3z^2 +7z
= z(3z+7)
