29/12 : 1/2 - 5/12 : 1/2 - 1/2
29/12:1/2-5/12:1/2-1/2
mình cần gấp
=29/12.2-5/12.2-1/2
=(29/12-5/12).2-1/2
=2.2-1/2
=4-1/2
=8/4-1/2
=7/2
12) √15-6√6 + √35-12√6
13) √46-6√5 - √29-12√5
14) (2-√3) √7+4√3
15) (4+√5)(√10-√6) √4-√15
16) √25-16 -6√1/3 - 2/1+√3
17) (1+√2+√3) (1+√2-√3)
12) \(\sqrt{15-6\sqrt{6}}+\sqrt{35-12\sqrt{6}}\)
\(=3-\sqrt{6}+3\sqrt{3}-2\sqrt{2}\)
13) \(\sqrt{46-6\sqrt{5}}-\sqrt{29-12\sqrt{5}}\)
\(=3\sqrt{5}-1-2\sqrt{5}+3\)
\(=\sqrt{5}+2\)
Bài 2: Tính hợp lý
1/ (-105). 47 -105. 53; 2/ 45 – 5. (12 + 9)
3/ 24. (16 – 5) – 16. (24 - 5) 4/ 29. (19 – 13) – 19. (29 – 13)
5/ 31. (-18) + 31. ( - 81) – 31 6/ (-12).47 + (-12). 52 + (-12)
Em nến gõ bằng công thức toán học em nhé. Như vậy mọi người nới hiểu đúng đề bài để trợ giúp cho em một cách tốt nhất em ạ!
a) A=\(\sqrt{\left(4-\sqrt{15}\right)^2+\sqrt{15}}\)
b) B=\(\sqrt{\left(2-\sqrt{3}\right)^2}+\sqrt{\left(1-\sqrt{3}\right)^2}\)
c) C=\(\sqrt{49-12\sqrt{5}}-\sqrt{49+12\sqrt{5}}\)
d)D=\(\sqrt{29+12\sqrt{5}-\sqrt{29-12\sqrt{5}}}\)
a: Sửa đề: \(A=\sqrt{\left(4-\sqrt{15}\right)^2}+\sqrt{15}\)
\(=4-\sqrt{15}+\sqrt{15}=4\)
b: \(A=2-\sqrt{3}+\sqrt{3}-1=1\)
c: \(C=3\sqrt{5}-2-3\sqrt{5}-2=-4\)
d: Sửa đề: \(D=\sqrt{29+12\sqrt{5}}-\sqrt{29-12\sqrt{5}}\)
\(=2\sqrt{5}+3-2\sqrt{5}+3\)
=6
a) \(A=\sqrt{\left(4-\sqrt{15}\right)^2}+\sqrt{15}\)
\(A=\left|4-\sqrt{15}\right|+\sqrt{15}\)
\(A=4-\sqrt{15}+\sqrt{15}\)
\(A=4\)
b) \(B=\sqrt{\left(2-\sqrt{3}\right)^2}+\sqrt{\left(1-\sqrt{3}\right)}\)
\(B=\left|2-\sqrt{3}\right|+\left|1-\sqrt{3}\right|\)
\(B=2-\sqrt{3}-1+\sqrt{3}\)
\(B=1\)
c) \(C=\sqrt{49-12\sqrt{5}}-\sqrt{49+12\sqrt{5}}\)
\(C=\sqrt{\left(3\sqrt{5}\right)^2-2\cdot3\sqrt{15}\cdot2+2^2}-\sqrt{\left(3\sqrt{5}\right)^2+2\cdot3\sqrt{5}\cdot2+2^2}\)
\(C=\sqrt{\left(3\sqrt{5}-2\right)^2}-\sqrt{\left(3\sqrt{5}+2\right)^2}\)
\(C=\left|3\sqrt{5}-2\right|-\left|3\sqrt{5}+2\right|\)
\(C=3\sqrt{5}-2-3\sqrt{5}-2\)
\(C=-4\)
d) \(D=\sqrt{29+12\sqrt{5}}-\sqrt{29-12\sqrt{5}}\)
\(D=\sqrt{\left(2\sqrt{5}\right)^2+2\cdot2\sqrt{5}\cdot3+3^2}-\sqrt{\left(2\sqrt{5}\right)^2-2\cdot2\sqrt{5}\cdot3+3^3}\)
\(D=\sqrt{\left(2\sqrt{5}+3\right)^2}-\sqrt{\left(2\sqrt{5}-3\right)^2}\)
\(D=\left|2\sqrt{5}+3\right|-\left|2\sqrt{5}-3\right|\)
\(D=2\sqrt{5}+3-2\sqrt{5}+3\)
\(D=6\)
1. (-12)+(-15)+(-31) | 2. 25+37-59 | 3. (-12)+13-(-60)
4. 24:(-2)+(-5) | 5. 32.(-2)+64 | 6. 18.3+(-50):5
7. (-24)+37+163+(-176) | 8. 125+217+(-625)+529 | 9. 29+132+237+868+763
10. (-87)+126+187+74 | 11. 29.87+29.13 | 12. 123.(-29)-23.(-29)
13. 31.(-18)+31.(-81)-31 | 14.(-12).47+(-12).52+(-12) | 15. 24.(16-5)-16.(24-5)
16. 29.(29-3)-19.(29-13) | 17. -452-(-67+75-452) | 18. -(-171+89+223)-(71-111)+223
19. 21.83-3.7.(-17) | 20. 35-{12-[-14+(-2)]} | 21.5+10+15+20+....+1000
22. 3-6+9-12+....+195-198
\(\dfrac{-29}{12}+1+\dfrac{19}{-12}\)\(\le\)x\(\le\dfrac{-1}{3}+\dfrac{3}{4}+\dfrac{7}{12}\)
\(\dfrac{-5}{3}+1+\dfrac{1}{-3}\le x\le\dfrac{8}{10}+\dfrac{1}{5}+2\)
Tìm x:a) x - 2 + 7 = 1 . 3 . -9
b) 4 . x - 1 = (-5) 5 12 2 4 16 9 2 9
c) -2 . x + 5 = 7
d) 2 . x : 7 . 1 = 29 3 8 12 5 3 8 15
bài 1
x - 2/5 + 7/12 = 1/2 * 3/4 * -9/16
4/9 * x - 1/2 = [ -5/9 ]
-2/3 * x + 5/8 = 7/12
2/5 * x : 7/3 * 1/8 = 29/15
a,x=-757/1920 b,x=-1/8 c,x=1/16 d,x=90/2/9
Tìm x:a) x - 2 + 7 = 1 . 3 . -9
b) 4 . x - 1 = (-5) 5 12 2 4 16 9 2 9
c) -2 . x + 5 = 7
d) 2 . x : 7 . 1 = 29 3 8 12 5 3 8 15