1 If the fourth power of the polynomial x-(a-1) the third power of x +(b+3)x- 1 does not contain the third power of x and the x term, find the value of 3a+b.

A= 1 b=-3 3a+b=0。

2 The quadratic power of three monomials ① π x ②-10 cubic power ③-? The cubic power of XY is arranged in descending order (fill in the serial number)

2 。 3 。 1

Arrange the cubic power of polynomial 5xy-3x and the quadratic power of -5+x according to the exponent of the letter X from big to small.

-3x cubic y quadratic power +x quadratic power +y cubic power +5xy-5.