下列运算中,正确的是 ( )
3 y + 5 y = 8 y 2
3 y - 5 y = - 2
3 y × 5 y = 15 y 2
3 y ÷ 5 y = 3 5 y
下列计算正确的是 ( )
a 2 + a 3 = a 5
a 8 ÷ a 4 = a 4
( - 2 ab ) 2 = - 4 a 2 b 2
( a + b ) 2 = a 2 + b 2
5 ab - 3 a = 2 b
( - 3 a 2 b ) 2 = 6 a 4 b 2
( a - 1 ) 2 = a 2 - 1
2 a 2 b ÷ b = 2 a 2
下列四个算式中,正确的是 ( )
a + a = 2 a
a 5 ÷ a 4 = 2 a
( a 5 ) 4 = a 9
a 5 - a 4 = a
下列计算结果是 x 5 的为 ( )
x 10 ÷ x 2
x 2 · x 3
( x 2 ) 3
x 6 - x
a 6 + a 6 = a 12
a 6 × a 2 = a 8
a 6 ÷ a 2 = a 3
( a 6 ) 2 = a 8
a 3 + a 2 = a 5
a 3 · a 2 = a 6
( a 2 ) 3 = a 5
a 6 ÷ a 2 = a 4
a 2 · a = a 2
a 2 b - 2 b a 2 = - a 2 b
( - 3 2 a ) 3 = - 9 8 a 3
a 2 · a 3 = a 6
a 3 ÷ a 2 = a
b 3 · b 3 = 2 b 3
( a 5 ) 2 = a 10
a - ( b + c ) = a - b + c
下列运算正确的是 ( )
2 x · 3 x = 6 x
3 x - 2 x = x
( 2 x ) 2 = 4 x
( x 2 ) 4 = x 6
2 a + 3 a = 5 a 2
( a + 2 b ) 2 = a 2 + 4 b 2
( - a b 2 ) 3 = - a 3 b 6
( - a 3 ) 2 = - a 6
2 a 2 + 3 a 2 = 6 a 2
2 a 2 · a 3 = 2 a 6
( - b 2 2 a ) 3 = - b 6 8 a 3
3 x + 2 x = 5 x 2
3 x · 2 x = 6 x
3 x ÷ 2 x = 2 3
2 a 2 · 3 a 2 = 6 a 2
( a - b ) 2 = a 2 - b 2
- a 2 + 2 a 2 = a 2