2,7,28,63 ( )215 A.116 B.126 C.138 D.142
2,7,28,63 ( )215 A.116 B.126 C.138 D.142
选择题.2,7,28,63,126,( ). A.215 B.216 C.217 D.218
2,7,28,63,( ),215.A,125;B,126;C,127;D,128.
数列2,15,7,40,77 () A、96 B、126 C、138 D、156
已知a+c-7=0,求(a+b)²-2a(b-c)+2b(c-b)+(c-d)²的值
若a/b=c/d=5/7(2b-3d不等于0),则2a-3c/2b-3d等于多少?
设a,b,c,d为正数,求证(a+c/a+b)+(b+d/b+c)+(c+a/c+d)+(d+b/d+a)≥4
2,9,28,65,() A、128 B、124 C、126 D、129
63 26 7 0 -2 -9 ( )A-18 B-20 C-26 D-28
63,26,7,0,-2,-9,( A.-18 B.-20 C.-26 D.-28答案选D,
a,b,c,d>0 证(a/(b+2c+3d))+(b/(c+2d+3a))+(c/d+2a+3b))+(d/(a+2b
[a,b)×[c,d