can someone help me solve this equation? 4x2 – 43x + 30 = 0?

Q1: 4x² + 43x + 30 = 0
x² + 43/8x = 15/2 + (43/8)²
x² + 43/8x = 480/64 + 1,849/64
(x + 43/8)² = 1,369/64
x + 43/8 = 37/8

x = 37/8 - 43/8, x = - 6/8, x = - 3/4
x = - 37/8 - 43/8, x = - 80/8, x = - 10

Answer: x = - 3/4, - 10

Q2: 4x² + 4x = 99
x² + 1/2x = 99/4 + (1/2)²
x² + 1/2x = 99/4 + 1/4
(x + 1/2)² = 100/4
x + 1/2 = +/- 5

x = 5 - 1/2, x = 4 1/2
x = - 5 - 1/2, x = - 5 1/2

Answer: x = 4 1/2, - 5 1/2

8x^3 - 2x^2 - 43x + 30 = 0. factors into 3 equations and 3 values of x. (x - 2)(2x + 5)(4x - 3) = 0. Set each binomial equation equivalent to 0. x - 2 = 0. x = 2. answer. 2x + 5 = 0. 2x = - 5. x = - 5/2. answer. 4x - 3 = 0. 4x = 3. x = 3/4. answer.

1)
4x^2 - 43x + 30 = 0
4x^2 - 3x - 40x + 30 = 0
(4x^2 - 3x) - (40x - 30) = 0
x(4x - 3) - 10(4x - 3) = 0
(4x - 3)(x - 10) = 0

4x - 3 = 0
4x = 3
x = 3/4 (0.75)

x - 10 = 0
x = 10

∴ x = 3/4 (0.75), 10
____________________________

2)
4x^2 + 4x = 99
4x^2 + 4x - 99 = 0
4x^2 + 22x - 18x - 99 = 0
(4x^2 + 22x) - (18x + 99) = 0
2x(2x + 11) - 9(2x + 11) = 0
(2x + 11)(2x - 9) = 0

2x + 11 = 0
2x = -11
x = -11/2 (-5.5)

2x - 9 = 0
2x = 9
x = 9/2 (4.5)

∴ x = -11/2 (-5.5), 9/2 (4.5)

4x^2-40x-3x+30=0

4x(x-10)-3(x-10)=0

(4x-3)(x-10)=0

x=3/4 or x=10.