If x ≠ 0 and a ≠ 0, solve :

Given, Hence, x = a + b or -(a + b).

Find the value of x, if a + 7 = 0; b + 10 = 0 and 12x² = ax - b.

Use the substitution 2x + 3 = y to solve for x, if 4(2x + 3)² - (2x + 3) - 14 = 0.