Split 90 into two parts so tha one part is 4 times the other part

so, we'll end up with two parts, one being 4 times larger than the other, namely if the other is 1 slice, then the large part is 4 slices, meaning both parts will be on a 4:1 ratio.

well, simply enough, we can simply split 90 in (4+1) pieces, and then distribute accordingly to each part

step-by-step explanation: a reaction is first order. if the initial reactant concentration is 0.0200 m, and 25.0 days later the concentration is 6.25 x 10-4 m, then its half-life is: