viet cac bieu thuc sau duoi dang tich:
a,1,24\(^3\)-0,24\(^3\)
b,(a-1)\(^3\)+(a+1)\(^3\)
c, a\(^6\)-b\(^6\)
viet cac bieu thuc sau duoi dang tich:
a,1,24\(^3\)-0,24\(^3\)
b,(a-1)\(^3\)+(a+1)\(^3\)
c, a\(^6\)-b\(^6\)
viet cac bieu thuc sau duoi dang tich:
b,(a-1)\(^3\)-(a+1)\(^3\)
\(\left(a-1\right)^3-\left(a+1\right)^3=a^3-3a^2+3a-1-a^3-3a^2-3a-1=-6a^2-2=-2\left(3a^2+1\right)\)
viet cac bieu thuc sau duoi dang tich:
b,(a-1)\(^3\)-(a+1)\(^3\)
\(\left(a-1\right)^3-\left(a+1\right)^3\)
\(=\left[\left(a-1\right)-\left(a+1\right)\right]\left[\left(a-1\right)^2+\left(a-1\right)\left(a+1\right)+\left(a+1\right)^2\right]\)
\(=\left(-2\right)\left(a^2-2a+1+a^2-1+a^2+2a+1\right)\)
\(=\left(-2\right)\left(3a^2+1\right)\)
viet cac bieu thuc sau duoi dang tich:
a, a\(^6\)-b\(^6\)
\(a^6-b^6=\left(a^3\right)^2-\left(b^3\right)^2=\left(a^3-b^3\right)\left(a^3+b^3\right)=\left(a-b\right)\left(a^2+ab+b^2\right).\left(a+b\right)\left(a^2-ab+b^2\right)\)
viet cac bieu thuc sau duoi dang tich:
a, -64+(x-3)\(^3\)
\(a,\left(-64\right)+\left(x-3\right)^3\)
\(=\left(-4\right)^3+\left(x-3\right)^3\)
\(=\left(-4+x-3\right)\left[\left(-4\right)^2-\left(-4\right)\left(x-3\right)+\left(x-3\right)^2\right]\)
viet cac bieu thuc sau duoi dang tich:
a, -64+(x-3)\(^3\)
viet cac bieu thuc sau duoi dang tich:
a, -64+(x-3)\(^3\)
\(a,-64+\left(x-3\right)^3\)
\(=\left(-4\right)^3+\left(x-3\right)^3\)
\(=\left(-4+x-3\right)\left[\left(-4\right)^2-\left(-4\right)\left(x-3\right)+\left(x-3\right)^2\right]\)
\(=\left(x-7\right)\left(16+4x-12+x^2-6x+9\right)\)
\(=\left(x-7\right)\left(x^2-2x+13\right)\)
viet cac bieu thuc sau duoi dang tich:
a, -64+(x-3)\(^3\)
nho cac ban giup minh nhe
1.tim x thuoc N biet:
a)(2x+1)mu 3=125 b)(x-5)mu 4=(x-5)mu 6 c)2 mu x-15=17 d)(7x-11)mu 3=2 mu 5. 5mu 2+200
2.viet cac tich sau hoac thuong duoi dang luy thua cua mot so:
a)2 mu 5 . 8 mu 4 b)25.125 c)25 mu 5:25 mu 7
3.viet cac tich, thuong sau duoi dang luy thua:
a) 2 mu 10:8 mu 3 b)12 mu 7:6 mu 7 c)5 mu 8:25 mu 2
4.tinh gia tri cac bieu thuc sau:
a mu3 . a mu 9 (a mu 5)mu7 (a mu 6)mu 4. a mu 12 4.5 mu 2-2.3 mu 2
Bài 1 :
a) (2x + 1)3 = 125
=> (2x + 1)3 = 53
=> 2x + 1 = 5
=> 2x = 5 - 1
=> 2x = 4
=> x = 2
b) (x - 5)4 = (x - 5)6
Với hai mũ khác nhau , ta chỉ có thể tìm được giá trị biểu thức bằng 1 hoặc 0 (giá trị của chúng bằng nhau)
+) (x - 5)4 = (x - 5)6 = 0
=> (x - 5)4 = 0
=> (x - 5)4 = 04
=> x - 5 = 0 => x = 0 + 5 = 5
+) (x - 5)4 = (x- 5)6 = 1
=> (x - 5)4 = 1
=> (x - 5)4 = 14
=> x - 5 = 1
=> x = 1 + 5
=> x = 6
Bài 4 :
a3 . a9 = a3 + 9 = a12
(a5)7.(a6)4 .a12 = a35 . a24 . a12 = a35 + 24 + 12 = a71
4.52 - 2.32 = 4.25 - 2.9
= 100 - 18
= 82
mong cac ban giup, minh can gap lam,tuy minh trinh bay hoi xau nhung mong cac ban giup
3.viet cac tich, thuong sau duoi dang luy thua:
a) \(\dfrac{2^{10}}{8^3}\)
\(=\dfrac{2^{10}}{\left(2^3\right)^3}\)
\(=\dfrac{2^{10}}{2^9}\)
\(=2^1\)