The diagonals of a square bisect one another and are perpendicular.
so 21x+ 16.5 = 90
subtract 16.5 from each side
21x = 73.5
divide by 21 on each side
21x/21 = 73.5 /21
x = 3.5
You would do 163 ÷ 9 and you will get your answer
Take out the GCF of 75 and 12 which is 3:-
= 3(25t^2 + 4)
That's it
18.56, 18.57, 18.58 or 18.59?