Step-by-step explanation:
1.7x² - 63 = 0
1.7x² = 63
x² = 63/1.7 = 37.05882353...
x = ±sqrt(37.05882353...) =
= 6.087595874...
or
= -6.087595874...
x² = (6.087595874...)² = (-6.087595874...)² =
= 37.05882353...
1.7 × 37.05882353... = 63
63 - 63 = 0
0 = 0
all correct.
2.2×(x - 3)² = 18
(x - 3)² = 18/2.2 = 8.1818181818...
x - 3 = ±sqrt(8.1818181818...)
x = sqrt(8.1818181818...) + 3 = 5.860387768...
or
x = -sqrt(8.1818181818...) + 3 = 0.139612232...
x - 3 = 2.860387768...
or
= -2.860387768...
(x - 3)² = (2.860387768...)² = (-2.860387768...)² =
= 8.1818181818...
2.2×8.1818181818... = 18
18 = 18
all correct.