计算或化简:(1)(a?5)12.(a12)13(a>0)(2)设3x=4y=36,求2x+1y
计算或化简:(1)(a?5)12.(a12)13(a>0)(2)设3x=4y=36,求2x+1y....
计算或化简:(1)(a?5)12.(a12)13(a>0)(2)设3x=4y=36,求2x+1y.
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(1)
=
=
=
=a2;
(2)由3x=4y=36,得x=log336,y=log436.
+
=
+
=
+
=
+
=
(a?5)
|
=
a?
|
a?
|
a4 |
(2)由3x=4y=36,得x=log336,y=log436.
2 |
x |
1 |
y |
2 |
log336 |
1 |
log436 |
=
2 | ||
|
1 | ||
|
2lg3 |
lg36 |
lg4 |
lg36 |
lg9+lg4 |