Step-by-step explanation:
Rate of growth equals 420/100 = 4.2 times per hour
So after t=three hours,
size of culture = 100*(4.2)^t = 100*4.2^3=7408.8 bacteria,
round to nearest unit 7409 bacteria after three hours (after initial size of 100).
The answer is 2^(9/10). I did it assuming with the ^5 you mean the 5th root of 4
Angle SRT is undetermined by the question.
A diameter always subtends a right angle (Thales' Theorem, the first in geometry) so we can be assured SRU, STU, RUT and RST are right angles.
5x + 2y = 7 . . . (1)
y = x + 1 . . . (2)
Putting (2) into (1) gives
5x + 2(x + 1) = 7 => 5x + 2x + 2 = 7 => 7x = 7 - 2 = 5 => x = 5/7
From (2) y = 5/7 + 1 = 12/7
Therefore, solution is {(5/7, 12/7)}