Answer:
Step-by-step explanation:
2{5x²-15+(-9xy²)}-(2y²+4x-xy²)+3x²
=2{5x²-15-9xy²}-(2y²+4x-xy²)+3x²
=10x²-30-18xy²-2y²-4x+xy²+3x²
=13x²-2y²-17xy²-4x-30
I'm not good at math i cant help
I don't quite understand the ten strategy, or what EXACTLY you're asking. But, what you can do is when you add a one digit number plus a nine, just change the nine to a ten and subtract one. It is very easy. So, 7+10 equals 17, subtract one and you get 16 which is 7+9. It is always one less than anything plus 10.
Answer:
-1.5,-1,0,0.5,1 is the answer