Whenever a number is beside a parenthesis without a sign it means multiplication. So you would use PEMDAS work in parenthesis then exponents, multiplication (from left to right) addition and subtraction (from left to right). so you would add 20+3 and get 23 then multiply that by -5 to get -115 as your answer.
Rick started with 10/10 of the grapes because he had all of them at the start.
Then he gave 2/10 and 4/10 of the grapes away.
10/10 - 2/10 - 4/10 = 4/10 = 2/5 left
answer: Rick had 2/5 of the grapes left.
I don't know what the "lowest y-intercept means" so if you can reiterate and clarify I'd appreciate it, but if you understand what you're looking for then I assume that a graph would be helpful. An online useful graphing site I like is desmos. Hope I helped.
I don’t understand what the question is telling me
Sine of angle = opposite ÷ hypotenuse
sin 20 = 
x = 
x = 40.9 (rounded up to nearest tenth)