计算:
(1) a ( 2 a + 3 b ) + ( a - b ) 2 ;
(2) x 2 - 9 x 2 + 2 x + 1 ÷ ( x + 3 - x 2 x + 1 ) .
计算 x 4 ÷ x 结果正确的是 ( )
x 4
x 3
x 2
x
(1) ( x - y ) 2 + x ( x + 2 y ) ;
(2) ( 1 - a a + 2 ) ÷ a 2 - 4 a 2 + 4 a + 4 .
计算3 a 6÷ a的结果是( )
3a 6
2a 5
2a 6
3a 5
(1)计算: 4 × ( - 3 ) + | - 8 | - 9 + ( 7 ) 0 .
(2)化简: ( a - 5 ) 2 + 1 2 a ( 2 a + 8 ) .
已知 ( a + b ) 2 = 49 , a 2 + b 2 = 25 ,则 ab = ( )
24
48
12
2 6
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
下列计算正确的是 ( )
( x 2 ) 3 = x 5
x 2 + x 2 = x 4
x 2 ⋅ x 3 = x 5
x 6 ÷ x 3 = x 2
(1)计算: ( 1 + a ) ( 1 - a ) + ( a + 3 ) 2 .
(2)解不等式组: 2 x + 1 < 9 3 - x ⩽ 0 .
计算 a 3 ⋅ ( - a ) 的结果是 ( )
a 2
- a 2
a 4
- a 4
计算 ( - a ) 2 ⋅ a 4 的结果是 ( )
a 6
- a 6
a 8
- a 8
已知 x = 1 6 ,求 ( 3 x - 1 ) 2 + ( 1 + 3 x ) ( 1 - 3 x ) 的值.
计算: x ( x + 2 ) + ( 1 + x ) ( 1 - x ) .
计算: 2 × 2 - 1 = .
计算: 2 a + 3 a = .