1)Tính:
a)√5 - √15/√3 -1 +1/2+√3 - √(√5-√3)^2
b)√162 - 2√72 + 5/3√18
3) Tìm x của N biết a) 80 - ( 2 + 2x ) : 2 = 40 b) 11^2 - 121 = 0 c) 5^x+3 - 7 × 5^2 = 5^2 × 18 d) x^10 = x e) x^10 = 1^x g) ( 2x - 15 )^5 = ( 2x - 15 )^3 4) Thực hiện phép tính a) 5^3 ÷ 5^2 + 2^2 × 3 b) 4^3 × 125 - 125 ÷ 5^2 c) 6^2 × 28 + 72 × 6^2 d) 5^6 ÷ 5^4 + 3 × 3^2 - 80 e) 2^3 × 19 - 2^3 × 14 × 1^2021
bài 1, tính
a, [-6-2].[-6+2]
b, [7.3-3]:[-6]
c, [-5+9] .[-4]
d, 72:[-6.2+4]
e, -3.7-4.[-5]+1
f,18-10:[+2]-7
g, 15:[-5].[-3]-8
h, [6.8-10:5]+3.[-7]
a, (-6-2).(-6+2)
=(-6)2-22
=36-4
=32
Mấy câu kia dễ mà bn tự lm nha
a, ( -6 - 2 ) . ( -6 + 2 )
= -8 . ( -4 )
= 32
Mấy câu kia tương tự
#hoc_tot#
Bài 3: Tìm x của N
a)80-(2+2x)÷2=40
b)11^2-121=0
c)5^x+3-7×5^2=5^2×18
d)x^10=x
e)x^10=1^x
g)(2x-15)^5=(2x-15)^3
Bài 4: Thực hiện phép tính
a)5^3÷5^2+2^2×3
b)4^3×125-125÷5^2
c)6^2×28+72×6^2
d)5^6÷5^4+3×3^2-80
e)2^3×19-2^3×14×1^2021
Cho mình câu chả lời sớm nhất vào 4h30 chiều ngày 28/9/2021
Bài 1 Tính nhanh
a) -3/7 + 5/13 + 3/7
b) -5/21+-2/21+8/24
c) -5/11+(-6/11+2)
d) (-1/32+1/2)+15/32
e)5/17+ -6/13 + 3/4 + 7/-13+12/17
f) 7/23+-18/18+-4/9+16/23+-5/8
g)1/3+-3/4+3/5+-1/36+1/15+-2/9
h)-1/2+1/3+-1/4+-2/8+4/18+4/9
a)\(-\dfrac{3}{7}+\dfrac{5}{13}+\dfrac{3}{7}\)
=\(\left(-\dfrac{3}{7}+\dfrac{3}{7}\right)+\dfrac{5}{13}\)
=\(0+\dfrac{5}{13}\)
=\(\dfrac{5}{13}\)
Thực hiện dãy tính:
a) ( 1/2 - 1/7 ) + -1/3 . 3 4/7 - 0.75
b) ( 6/14 - -18/36 - 5/15 ) : ( 0,2 - 1 4/ 5 )
c) 11/ 32 : ( 14/18 + 16/27) - (2/3 - 5/15 )
d) 4. ( -1/2 ) 2 - 2. ( - 2/3 ) 2 + 2 7/9 - (-18/48)
e) 1,4 . 15/49 - (4/5 + 2/3 ) : ( -2 1/5 )
g) -1/7. (9 1/2 - 8.75 ) : 2/7 + 0,675 : ( -1 2/3 )
1.b=5/2+5/6+5/18+5/54+5/162+5/486
2.c=3/2+3/8+3/32+3/128+3/512
a. Tìm a, biết: 1 - ( 5\(\dfrac{4}{9}\) + a - 7\(\dfrac{7}{18}\) ) : 15\(\dfrac{3}{4}\) = 0
b. Tính b = ( \(\dfrac{2}{15}\) + \(\dfrac{5}{3}\) - \(\dfrac{3}{5}\) ) : ( \(4\dfrac{2}{3}\) - \(2\dfrac{1}{2}\) )
a: \(1-\left(5\dfrac{4}{9}+a-7\dfrac{7}{18}\right):15\dfrac{3}{4}=0\)
=>\(\left(5+\dfrac{4}{9}+a-7-\dfrac{7}{18}\right):\dfrac{63}{4}=1\)
=>\(\left(a-2+\dfrac{1}{18}\right)=\dfrac{63}{4}\)
=>\(a-\dfrac{35}{18}=\dfrac{63}{4}\)
=>\(a=\dfrac{63}{4}+\dfrac{35}{18}=\dfrac{637}{36}\)
b: \(B=\left(\dfrac{2}{15}+\dfrac{5}{3}-\dfrac{3}{5}\right):\left(4\dfrac{2}{3}-2\dfrac{1}{2}\right)\)
\(=\dfrac{2+5\cdot5-3^2}{15}:\left(4+\dfrac{2}{3}-2-\dfrac{1}{2}\right)\)
\(=\dfrac{2+4^2}{15}:\left(2+\dfrac{2}{3}-\dfrac{1}{2}\right)\)
\(=\dfrac{18}{15}:\dfrac{13}{6}=\dfrac{6}{5}\cdot\dfrac{6}{13}=\dfrac{36}{65}\)
Tính:
\(A=3\sqrt{20}-\sqrt{45}+2\sqrt{18}+\sqrt{72}\)
\(B=\dfrac{12}{3-\sqrt{5}}-\dfrac{16}{\sqrt{5}+1}\)
\(C=10\sqrt{\dfrac{1}{5}}+\dfrac{1}{5}\sqrt{125}-2\sqrt{20}\)
\(E=\sqrt{\left(\sqrt{3}+1\right)^2}-\sqrt{\left(\sqrt{3}-2\right)^2}\)
\(F=\sqrt{6+2\sqrt{5}}-\sqrt{9-4\sqrt{5}}\)
a) Ta có: \(A=3\sqrt{20}-\sqrt{45}+2\sqrt{18}+\sqrt{72}\)
\(=6\sqrt{5}-3\sqrt{5}+6\sqrt{2}+6\sqrt{2}\)
\(=3\sqrt{5}+12\sqrt{2}\)
b) Ta có: \(B=\dfrac{12}{3-\sqrt{5}}-\dfrac{16}{\sqrt{5}+1}\)
\(=\dfrac{12\left(3+\sqrt{5}\right)}{4}-\dfrac{16\left(\sqrt{5}-1\right)}{4}\)
\(=3\left(3+\sqrt{5}\right)-4\left(\sqrt{5}-1\right)\)
\(=9+3\sqrt{5}-4\sqrt{5}+4\)
\(=13-\sqrt{5}\)
c) Ta có: \(C=10\sqrt{\dfrac{1}{5}}+\dfrac{1}{5}\sqrt{125}-2\sqrt{20}\)
\(=\dfrac{10}{\sqrt{5}}+\dfrac{1}{5}\cdot5\sqrt{5}-2\cdot2\sqrt{5}\)
\(=2\sqrt{5}+\sqrt{5}-4\sqrt{5}\)
\(=-\sqrt{5}\)
e) Ta có: \(E=\sqrt{\left(\sqrt{3}+1\right)^2}-\sqrt{\left(\sqrt{3}-2\right)^2}\)
\(=\sqrt{3}+1-2+\sqrt{3}\)
\(=2\sqrt{3}-1\)
f) Ta có: \(F=\sqrt{6+2\sqrt{5}}-\sqrt{9-4\sqrt{5}}\)
\(=\sqrt{5}+1-\sqrt{5}+2\)
=3
Tính:
\(A=3\sqrt{20}-\sqrt{45}+2\sqrt{18}+\sqrt{72}\)
\(B=\dfrac{12}{3-\sqrt{5}}-\dfrac{16}{\sqrt{5}+1}\)
\(C=10\sqrt{\dfrac{1}{5}}+\dfrac{1}{5}\sqrt{125}-2\sqrt{20}\)
\(E=\sqrt{\left(\sqrt{3}+1\right)^2}-\sqrt{\left(\sqrt{3}-2\right)^2}\)
\(F=\sqrt{6+2\sqrt{5}}-\sqrt{9-4\sqrt{5}}\)
e) Ta có: \(E=\sqrt{\left(\sqrt{3}+1\right)^2}-\sqrt{\left(\sqrt{3}-2\right)^2}\)
\(=\sqrt{3}+1-2+\sqrt{3}\)
\(=2\sqrt{3}-1\)
f) Ta có: \(F=\sqrt{6+2\sqrt{5}}-\sqrt{9-4\sqrt{5}}\)
\(=\sqrt{5}+1-\sqrt{5}+2\)
=3
a) Ta có: \(A=3\sqrt{20}-\sqrt{45}+2\sqrt{18}+\sqrt{72}\)
\(=6\sqrt{5}-3\sqrt{5}+6\sqrt{2}+6\sqrt{2}\)
\(=3\sqrt{5}+12\sqrt{2}\)
b) Ta có: \(B=\dfrac{12}{3-\sqrt{5}}-\dfrac{16}{\sqrt{5}+1}\)
\(=\dfrac{12\left(3+\sqrt{5}\right)}{4}-\dfrac{16\left(\sqrt{5}-1\right)}{4}\)
\(=3\left(3+\sqrt{5}\right)-4\left(\sqrt{5}-1\right)\)
\(=9+3\sqrt{5}-4\sqrt{5}+4\)
\(=13-\sqrt{5}\)