a.X x 5,2 : 4,5 = 10,5
b.5/7 x X + 2/7 x X = 2/3
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
a)x*5,2:4,5=10,4
x*5,2=10,4*4,5
x*5,2=46,8
x =46,8:5,2
x =9
b)5/7*x+2/7*x=2/3
x*(5/7+2/7)=2/3
x*1 =2/3
x =2/3:1
x =2/3
a.
\(x\times5,2\div4,5=10,4\)
\(x\times5,2=10,4\times4,5\)
\(x\times5,2=46,8\)
\(x=46,8\div5,2\)
\(x=9\)
b.
\(\dfrac{5}{7}\times x+\dfrac{2}{7}\times x=\dfrac{2}{3}\)
\(x\times\left(\dfrac{5}{7}+\dfrac{2}{7}\right)=\dfrac{2}{3}\)
\(x\times1=\dfrac{2}{3}\)
\(x=\dfrac{2}{3}\div1\)
\(x=\dfrac{2}{3}\)
a) X*5,2 : 4,5 =10,4
X*5,2=10,4*4,5
X*5,2=46,8
X =46,8:5,2
X =9
b) 5/7*x+2/7*x=2/3
(5/7+2/7)*x=2/3
1*x =2/3
x =2/3:1
x =2/3
a) 105,6 - x = 29,04
x = 105,6 - 29,04
x = 76,56
b) x : 7 = 4,5 × 3
x : 7 = 13,5
x = 13,5 × 7
x = 94,5
c) Sửa đề: x × 2,8 + x × 5,2 = 48
x × (2,8 + 5,2) = 48
x × 8 = 48
x = 48 : 8
x = 6
d) Sửa đề:
x × 12,25 + x × 2,75 = 1050
x × (12,25 + 2,75) = 1050
x × 15 = 1050
x = 1050 : 15
x = 70
a) \(105,6-x=29,04\)
\(x=105,6-29,04\)
\(x=76,2\)
b) \(x:7=4,5x3\)
\(x:7=13,5\)
\(x=13,5x7\)
\(x=94,5\)
c) Bạn xem lại đề
d) Bạn xem lại đề
a)\(\dfrac{x}{60}=-\dfrac{3}{4}\)
\(\Rightarrow x\cdot4=60\cdot\left(-3\right)\)
\(x\cdot4=-180\)
x=45
b)\(\dfrac{2}{5}=\dfrac{12}{x}\)
\(\Rightarrow2x=5\cdot12\)
\(2x=60\)
x=30
c)\(x-\dfrac{5}{7}=\dfrac{6}{21}\)
\(x=\dfrac{2}{7}+\dfrac{5}{7}\)
x=1
d)\(x+\dfrac{7}{8}=\dfrac{63}{24}\)
\(x=\dfrac{21}{8}-\dfrac{7}{8}\)
\(\dfrac{14}{8}\)
X+\(\dfrac{2}{7}\)=\(\dfrac{1}{2}\)
X = \(\dfrac{1}{2}\)-\(\dfrac{2}{7}\)
X = \(\dfrac{3}{14}\)
Chọn đáp án A. \(\dfrac{3}{14}\)
c1 = xy(x+y) - (x+y)
= (x+y)(xy-1)
c2 đề sai
c3 = a(x2+y)-b(x2+y)
= (x2+y)(a-b)
mk làm mẫu cho mấy câu thui nha (mỏi tay quá) hiii. vì đây là toán dạng cơ bản
a) x2 - 5x - 6 = 0
=> x2 - 2x - 3x - 6 = 0
=> (x2 - 2x) + (-3x - 6) = 0
=> x(x - 2) - 3 (x - 2) = 0
=> (x - 2) (x - 3) = 0
=> x - 2 = 0 => x = 2
x - 3 = 0 => x = 3
còn lại tương tự nhé!! 46566578768698945635655675656788787868789789879789098089364556546
b: \(x+\dfrac{5}{6}=\dfrac{3}{8}\)
=>\(x=\dfrac{3}{8}-\dfrac{5}{6}\)
=>\(x=\dfrac{9}{24}-\dfrac{20}{24}=-\dfrac{11}{24}\)
c: \(\dfrac{2}{3}x-\dfrac{1}{2}=\dfrac{5}{6}\)
=>\(\dfrac{2}{3}x=\dfrac{5}{6}+\dfrac{1}{2}=\dfrac{8}{6}=\dfrac{4}{3}\)
=>2x=4
=>x=4/2=2
d: \(\dfrac{x}{7}=\dfrac{6}{-21}\)
=>\(\dfrac{x}{7}=\dfrac{-2}{7}\)
=>x=-2
e: \(\left(\dfrac{7}{3}x-0,6\right):\dfrac{3^2}{5}=1\)
=>\(\dfrac{7}{3}x-0,6=\dfrac{3^2}{5}=1,8\)
=>\(\dfrac{7}{3}x=2,4\)
=>\(x=2,4:\dfrac{7}{3}=2.4\cdot\dfrac{3}{7}=\dfrac{7.2}{7}=\dfrac{36}{35}\)
f: \(\dfrac{x}{45}=\dfrac{5}{6}+\dfrac{-29}{30}\)
=>\(\dfrac{x}{45}=\dfrac{25}{30}-\dfrac{29}{30}=-\dfrac{4}{30}=-\dfrac{2}{15}\)
=>\(x=-\dfrac{2}{15}\cdot45=-6\)
g: \(\left(4,5-2x\right)\cdot\left(-\dfrac{1^4}{7}\right)=\dfrac{11}{14}\)
=>\(4,5-2x=\dfrac{11}{14}:\dfrac{-1}{7}=\dfrac{-11}{2}\)
=>\(2x=4,5+\dfrac{11}{2}=\dfrac{20}{2}=10\)
=>x=10/2=5
h: \(-\dfrac{2}{7}+\dfrac{4}{7}x=\dfrac{5}{7}\)
=>\(\dfrac{4}{7}x=\dfrac{5}{7}+\dfrac{2}{7}=\dfrac{7}{7}\)
=>4x=7
=>\(x=\dfrac{7}{4}\)
câu 1:
x2y+xy2-x-y
=(x2y-x)+(xy2y)
=x(xy-1)+y(xy-1)
=(x+y)(xy-1)
Câu 2:sai đề
Câu 3:
ax2+ay-bx2-by
=(ax2+ay)-(bx2+by)
=a(x2+y)-b(x2+y)
=(a-b)(x2+y)
Câu 4:
x(x+1)2+x(x-5)-5(x+1)2
=(x+1)2(x-5)+x(x-5)
=(x+5)[(x+1)2+x]
=(x+5)(x2+3x+1)
Câu 5:
3x2-12y2
=3(x2-4y2)
=3[(x)2-(2y)2]
=3(x-2y)(x+2y)
Câu 6:
5xy2-10xyz+5xz2
=5x(y2-2yz+z2)
=5(z-y)2
a)
X x 5,2 : 4,5 = 10 ,5
X x 5,2 = 10,5 x 4,5
X x 5,2 = 47,25
X = 47,25 : 5,2
X = 945/104
b)
5/7 x X + 2/7 x X = 2/3
X x ( 5/7 + 2/7 ) = 2/3
X x 1 = 2/3
x = 2/3 : 1
x = 2/3