Can someone help me with my homework? STEP BY STEP TROLLERS WIL BE REPORTED​

Given the two similar triangles, how do i find the missing length? if a=4, b=5, and b'=7.5 find a'

Acolony contains 1500 bacteria. the population increases at a rate of 115% each hour. if x represents the number of hours elapsed, which function represents the scenario? f(x) = 1500(1.15)" f(x) = 1500(115) f(x) = 1500(2.15) f(x) = 1500(215)

The measurement of one angle of a right triangle is 42° what is the measurement of the third angle? (there is no picture)