下列运算正确的是( )
(1)计算:()0 -()-2 +sin 30° (2)化简:
给出三个多项式:x2+x-1,x2+3x+1,x2-x,请你写出所有其中两个多项式的加法运算,并把运算结果因式分解.
计算:= .
下列计算正确的是 ( )
3 a + 2 b = 5 ab
( − 2 a ) 2 = − 4 a 2
( a + 1 ) 2 = a 2 + 2 a + 1
a 3 · a 4 = a 12
化简的结果是( )
下列计算正确的是( )
多项式8x2﹣3x+5与多项式3x3+2mx2﹣5x+7相加后,不含二次项,则常数m的值是 .
下列运算中,正确的是 ( )
a 2 + a = a 3
( - ab ) 2 = - a b 2
a 5 ÷ a 2 = a 3
a 5 ⋅ a 2 = a 10
计算: 2 a + 3 a = .
a 2 + a 2 = 2 a 4
a 2 ⋅ a = a 3
( 3 a ) 2 = 6 a 2
a 6 + a 2 = a 3
下列运算正确的是 ( )
2 x 2 + 3 x 3 = 5 x 5
( − 2 x ) 3 = − 6 x 3
( x + y ) 2 = x 2 + y 2
( 3 x + 2 ) ( 2 − 3 x ) = 4 − 9 x 2
下列式子正确的是 ( )
a 3 - a 2 = a
( a 2 ) 3 = a 6
a 3 ⋅ a 2 = a 6
( a 2 ) 3 = a 5
先化简,再求值:3-[7x-2(6x-8)-],其中x=-1.
2(a-b)-3(a+b)