Answer:
see explanation
Step-by-step explanation:
(a)
The student has distributed the second parenthesis by 1 instead of - 1
(b)
Given
(x² - 3x + 4) - (x³ + 7x - 2)
distribute the first parenthesis by 1 and the second by - 1, that is
= x² - 3x + 4 - x³ - 7x + 2 ← collect like terms
= - x³ + x² - 10x + 6
