14.下列运算正确的是( )
| A. | (ab)2=ab2 | B. | 3a+2a2=5a2 | C. | 2(a+b)=2a+b | D. | a•a=a2 |
11.下列计算正确的是( )
| A. | b3•b4=b7 | B. | (b3)4=b7 | C. | b3+b4=b7 | D. | b6÷b3=b2 |
10.
如图,AB是⊙O的直径,点D、E是半圆的三等分点,AE、BD的延长线交于点C,若CE=2,则图中阴影部分的面积是( )
| A. | $\frac{4}{3}$π-$\sqrt{3}$ | B. | π | C. | π-$\sqrt{3}$ | D. | $\sqrt{3}$ |
9.
如图,AB∥DE,AC⊥CD,并且∠A=35°,则∠D的度数为( )
0 282950 282958 282964 282968 282974 282976 282980 282986 282988 282994 283000 283004 283006 283010 283016 283018 283024 283028 283030 283034 283036 283040 283042 283044 283045 283046 283048 283049 283050 283052 283054 283058 283060 283064 283066 283070 283076 283078 283084 283088 283090 283094 283100 283106 283108 283114 283118 283120 283126 283130 283136 283144 366461
| A. | 55° | B. | 45° | C. | 30° | D. | 60° |