1. Work the problem backwards. Well you know that increased by 4 means adding so we do 25-4=21. 10 times what equals 21. To figure that out just do 21÷10=2.1.
So....(10•2.1)+4 ≤ 27 or 25 ≤ 27
6. This one has many possabilities. Well let's start by putting numbers in the equation. I know that 10 • 1/2 = 5 so anything above 10 can be our answer.
Eg. : 1/2 (12.9 +1) ≥ 5
Hoped I helped!
