Equation 2:
by2 - 8y + 4 = 0
One of the roots of equation 2 is 2/3. So,
b(2/3)2 - 8(2/3) + 4 = 0
4b/9 = 4/3
b = 3
Now, 3y2 - 8y + 4 = 0
3y2 - 6y - 2y + 4 = 0
3y(y - 2) - 2(y - 2) = 0
(y - 2)(3y - 2) = 0
y = 2, 2/3
The ratio of highest root of equation 1 to the highest root of equation 2 is 7: 4. So,
Highest root of equation 1 = 2 * 7/4 = 7/2
Now, Equation 1: ax2 - 9x + 7 = 0
a(7/2)2 - 9(7/2) + 7 = 0
49a/4 = 49/2
a = 2
So, 2x2 - 9x + 7 = 0
2x2 - 7x - 2x + 7 = 0
x(2x - 7) - 1(2x - 7) = 0
(2x - 7)(x - 1) = 0
x = 7/2, 1
(a + b)2x2 + (3ab + 1)x - 6 = 0
(2 + 3)2x2 + (3 * 2 * 3 + 1)x - 6 = 0
25x2 + 19x - 6 = 0
25x2 + 25x - 6x - 6 = 0
25x(x + 1) - 6(x + 1) = 0
(x + 1)(25x - 6) = 0
x = -1, 6/25