hi:) I need help with part 9(ii) ? Thanks :)!

Answer:
see explanation
Step-by-step explanation:
Given
2BD = 7BT , then
2(d - b ) = 7(t - b) ← distribute both sides
2d - 2b = 7t - 7b ( add 7b to both sides )
2d + 5b = 7t, thus
2[tex]\left[\begin{array}{ccc}10.5\\10\\\end{array}\right][/tex] + 5[tex]\left[\begin{array}{ccc}0\\3\\\end{array}\right][/tex] = 7t
[tex]\left[\begin{array}{ccc}21\\20\\\end{array}\right][/tex] + [tex]\left[\begin{array}{ccc}0\\15\\\end{array}\right][/tex] = 7t
[tex]\left[\begin{array}{ccc}21\\35\\\end{array}\right][/tex] = 7t , thus
t = [tex]\frac{1}{7}[/tex][tex]\left[\begin{array}{ccc}21\\35\\\end{array}\right][/tex] = [tex]\left[\begin{array}{ccc}3\\5\\\end{array}\right][/tex]
Hence T = (3, 5 )
Answer:
Please see the attached pictures for the full solution.
We reject x= -3 since x has to be between x=0 and x=10.5 since T lies on line BD.
We reject y= 1 since the y value has to be between 3 and 10 for T to lie on line BD.
Useful formula:
gradient=(y1-y2)/(x1-x2)
Further explanation:
1st picture, from line 12 to 13: cross multiply
line 14: expand
line 15: bring 9 over (or +9 on both sides)
line 16: ÷3 throughout
last picture: we have to show '(reject)' because whenever we introduce a square root, there must be a '±' sign.