A=3\(\sqrt{49}\)-\(\sqrt{25}\) ; B=\(\sqrt{\left(3-2\sqrt{5}\right)^2}-\sqrt{20}\)
Mik cần gấp nha mn
Những câu hỏi liên quan
Thực hiện phép tính:
a. \(\sqrt{25}+2\sqrt{49}\)
b. \(\sqrt{16}.\sqrt{25}+\sqrt{169}:\sqrt{49}\)
c. \(\sqrt{\left(3-\sqrt{7}\right)^2}+\sqrt{7}\)
d. \(2\sqrt{3}-\sqrt{75}+2\sqrt{12}\)
a)\(\sqrt{25}+2\sqrt{49}=5+2\cdot7=5+14=19\)
b) \(\sqrt{16}\cdot\sqrt{25}+\sqrt{169}:\sqrt{49}=4\cdot5+13:7=20+\dfrac{13}{7}\) = \(\dfrac{153}{7}\)
c) \(\sqrt{\left(3-\sqrt{7}\right)^2}+\sqrt{7}=3-\sqrt{7}+\sqrt{7}=3\)
d) \(2\sqrt{3}-\sqrt{75}+2\sqrt{12}=2\sqrt{3}-5\sqrt{3}+4\sqrt{3}\) \(=\sqrt{3}\)
Đúng 0
Bình luận (0)
Thực hiện phép tính:
a. \(\sqrt{25}+2\sqrt{49}\)
b. \(\sqrt{16}.\sqrt{25}+\sqrt{169}:\sqrt{49}\)
c. \(\sqrt{\left(3-\sqrt{7}\right)^2}+\sqrt{7}\)
d. \(2\sqrt{3}-\sqrt{75}+2\sqrt{12}\)
a) 2sqrt(25(x - 3)) - 1/2 * sqrt(4x - 12) + 1/7 * sqrt(49(x - 3)) = 20 b) sqrt(x ^ 2 - 6x + 9) = 2
B2 : Tính : a, left(sqrt{x}-3right).left(sqrt{x}+2right)b, left(sqrt{x}-sqrt{y}right).left(sqrt{x}+sqrt{y}right)c, left(sqrt{dfrac{25}{3}}-sqrt{dfrac{49}{3}}+sqrt{3}right).sqrt{3}d,left(1+sqrt{3}-sqrt{5}right).left(1+sqrt{3}+sqrt{5}right)
Đọc tiếp
B2 : Tính :
a, \(\left(\sqrt{x}-3\right)\)\(.\left(\sqrt{x}+2\right)\)
b, \(\left(\sqrt{x}-\sqrt{y}\right).\)\(\left(\sqrt{x}+\sqrt{y}\right)\)
c, \(\left(\sqrt{\dfrac{25}{3}}-\sqrt{\dfrac{49}{3}}+\sqrt{3}\right)\)\(.\sqrt{3}\)
d,\(\left(1+\sqrt{3}-\sqrt{5}\right)\)\(.\left(1+\sqrt{3}+\sqrt{5}\right)\)
a. \(\left(\sqrt{x}-3\right)\left(\sqrt{x}+2\right)=x-3\sqrt{x} +2\sqrt{x}-6=x-\sqrt{x}-6\)
b. \(\left(\sqrt{x}-\sqrt{y}\right)\left(\sqrt{x}+\sqrt{y}\right)=x-y\)
c. \(\left(\sqrt{\dfrac{25}{3}}-\sqrt{\dfrac{49}{3}}+\sqrt{3}\right).\sqrt{3}\)
\(=\left(\dfrac{5}{\sqrt{3}}-\dfrac{7}{\sqrt{3}}+\sqrt{3}\right).\sqrt{3}=\dfrac{5}{3}-\dfrac{7}{3}+9=\dfrac{25}{3}\)
d. \(\left(1+\sqrt{3}-\sqrt{5}\right)\left(1+\sqrt{3}+\sqrt{5}\right)\)
\(=\left(1+\sqrt{3}\right)^2-5=1+2\sqrt{3}+3-5=2\sqrt{3}-1\)
Đúng 2
Bình luận (1)
a)\(\sqrt{\dfrac{10000}{\sqrt{400}}}\)+\(\sqrt{\left(3\right)^2}\).\(\sqrt{6^4}\)
b)\(\sqrt{1600}\):\(\sqrt{25}\)+\(\sqrt{49}\).\(\sqrt{16}\)-\(\sqrt{\left(-10\right)^2}\)
giup mik ai nhanh mik se tick cho nhe
2: Giải phương trình a) 2sqrt(25(x - 3)) - 1/2 * sqrt(4x - 12) + 1/7 * sqrt(49(x - 3)) = 20 b) sqrt(x ^ 2 - 6x + 9) = 2
a: \(\Leftrightarrow2\cdot5\sqrt{x-3}-\dfrac{1}{2}\cdot2\sqrt{x-3}+\dfrac{1}{7}\cdot7\sqrt{x-3}=20\)
=>\(10\cdot\sqrt{x-3}=20\)
=>\(\sqrt{x-3}=2\)
=>x-3=4
=>x=7
b: =>|x-3|=2
=>x-3=2 hoặc x-3=-2
=>x=5 hoặcx=1
Đúng 1
Bình luận (0)
8 tháng 11 2021 lúc 14:57
tính
a) \(\sqrt{16}.\sqrt{25}+\sqrt{196}:\sqrt{49}\)
b) 36 : \(\sqrt{2.3^2.18}-\sqrt{169}\)
c) \(\sqrt{\sqrt{81}}\)
d) \(\sqrt{3^2+4^2}\)
a: \(=4\cdot5+14:7\)
=20+2
=22
Đúng 1
Bình luận (0)
Câu 11) Tínha) sqrt{25}+sqrt{49} b) sqrt{121}-sqrt{81}2) Với x -2 thì sqrt{2x+1} có nghĩa không3) Rút gọn biểu thức sau :a) sqrt{left(sqrt{3}-1right)^2}-sqrt{3} b) left(sqrt{28}-2sqrt{14}+sqrt{7}right)sqrt{7}+7sqrt{8} c) dfrac{sqrt{27}-sqrt{108}+sqrt{12}}{sqrt{3}}
Đọc tiếp
Câu 1
1) Tính
a) \(\sqrt{25}+\sqrt{49}\) b) \(\sqrt{121}-\sqrt{81}\)
2) Với x > -2 thì \(\sqrt{2x+1}\) có nghĩa không
3) Rút gọn biểu thức sau :
a) \(\sqrt{\left(\sqrt{3}-1\right)^2}-\sqrt{3}\) b) \(\left(\sqrt{28}-2\sqrt{14}+\sqrt{7}\right)\sqrt{7}+7\sqrt{8}\) c) \(\dfrac{\sqrt{27}-\sqrt{108}+\sqrt{12}}{\sqrt{3}}\)
1:
a: \(\sqrt{25}+\sqrt{49}=5+7=12\)
b: \(\sqrt{121}-\sqrt{81}=11-9=2\)
2: x>-2
=>2x>-4
=>2x+1>-3
=>Với x>-2 thì \(\sqrt{2x+1}\) chưa chắc có nghĩa
3:
a: \(\sqrt{\left(\sqrt{3}-1\right)^2}-\sqrt{3}\)
\(=\left|\sqrt{3}-1\right|-\sqrt{3}\)
\(=\sqrt{3}-1-\sqrt{3}=-1\)
b: \(\left(\sqrt{28}-2\sqrt{14}+\sqrt{7}\right)\cdot\sqrt{7}+7\sqrt{8}\)
\(=\left(3\sqrt{7}-2\sqrt{14}\right)\cdot\sqrt{7}+14\sqrt{2}\)
\(=21-14\sqrt{2}+14\sqrt{2}=21\)
c:
\(\dfrac{\sqrt{27}-\sqrt{108}+\sqrt{12}}{\sqrt{3}}\)
\(=\dfrac{3\sqrt{3}-6\sqrt{3}+2\sqrt{3}}{\sqrt{3}}=3+2-6=-1\)
Đúng 1
Bình luận (0)
\(\left(-3\right)^2.\dfrac{1}{3}-\sqrt{49}+\left(-5\right)^3:\sqrt{25}\)
\(=9\cdot\dfrac{1}{3}-7-125:5=3-7-25=3-32=-29\)
Đúng 0
Bình luận (0)
\(\left(-3\right)^2.\dfrac{1}{3}-\sqrt{49}+\left(-5\right)^3:\sqrt{25}\)
= 9 . \(\dfrac{1}{3}\)- 7 + -125 : 5 = 3 - 7 + -25 = 4 + -25 = -21
Đúng 0
Bình luận (0)