Step-by-step explanation:
the scanned description is very hard to understand.
so I think what happened :
16x² - 9 = 16
then the first error :
sqrt(16x²) - sqrt(9) = sqrt(16)
that is wrong, as you cannot split a + or - operation inside a sqrt function into + or - separate sqrt results of the parts.
so, correctly, the only possible transformation involving sqrt for both sides :
sqrt(16x² - 9) = sqrt(16)
but it would be even easier to clean up the various constant numbers with each other.
so,
16x² - 9 = 16
16x² = 25
and now we trashes the square root
sqrt(16x²) = sqrt(25)
4x = 5
x = 5/4 or x = -5/4
and I cannot see or understand for my life what the second equation was, as Daniel did something wrong, so I cannot deduct the original equation out of a supposedly wrong
y³ - 1 = 7
