1) 4a³ab-6a²b³b³-5ab×3a+7a³b×0,2b⁴=4a⁴b-6a²b^6-15a²b+1.4a³b^5=a²b(4a²-6b^5)-a²b(15+7/5ab⁴)=b(a²(4a²-6b^5)-a²(15+(7ab⁴)/5))=(5a²b(4a²-6b^5)-a²b(7ab⁴+75))/5=4a⁴b-(7a³b^5)/5-6a²b^6-15a²b=(a²b(20a²-7ab⁴-30b^5-75)/5
2) 3x(4x-1)-6x(1.5+2x)=4.8
12x²-3x-9x-12x²=4.8
-12x=4.8
x=4.8/(-12)
x=-0.4