Ответ:
5x-(2x-3y)=5x-2x+3y=3x-3y
(4x+2)+(-x-1)=4x+2-x-1=3x+1
3x²-(4x²+2y)=3x²-4x²-2y=-x²-2y
0,6a²-(0,5a2-0,4a)=0,6a²-0,5a²-0,4a=0,1a²-0,4a
2a²-(b²-3a²)=2a²-b²+3a²=5a²+b²
S10=2a1+9d
_________*2=(2a1+9d)*5=(2a1+9*6)*5=240
2 10a1+270=340
10a1=340-270
10a1=70
a1=7
a10=a1+9d
a10=7+9*6
a10=7+54
a10=61