7,5x. 519=520.511
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
25%x+7,5x=-21
1/4x+15/2x=-21
(1/4+15/2)x=-21
31/4x=-21
X= -21:31/4
X= -84/31
Vậy x=-84/31.
\(\left[7.5\cdot\left(-3.5\right)-2.5\cdot3.5\right]\cdot1.9:\left(-17.5\right)\)
\(=-3.5\cdot10\cdot\dfrac{1.9}{-17.5}\)
\(=\dfrac{35\cdot1.9}{17.5}=2\cdot1.9=3.8\)
\(\dfrac{\left[7.5\cdot\left(-3.5\right)-2.5\cdot3.5\right]\cdot1.9}{-17.5}\)
\(=\dfrac{-3.5\left(7.5+2.5\right)\cdot1.9}{-17.5}\)
\(=\dfrac{35\cdot1.9}{17.5}=2\cdot1.9=3.8\)
7,5*x+x*3,5=39,93
(7,5+3,5)*x=39,93
11x=39,93
x=39,93/11
x=3,63. Vậy x=3,63
Cách 1 :
Tổng là:
519 + 519 = 1038
Đáp số:1038
Cách 2 :
519 + 519
= 519 x 2
= 1038
\(7,5x:\left(9-6\dfrac{13}{21}\right)=7.\left(\dfrac{3}{5}\right)^2\\ 7,5x:\left(9-\dfrac{139}{21}\right)=7.\dfrac{9}{25}\\ 7,5x:\left(\dfrac{189}{21}-\dfrac{139}{21}\right)=\dfrac{63}{25}\\ 7,5x:\dfrac{50}{21}=\dfrac{63}{25}\\ 7,5x=\dfrac{63}{25}.\dfrac{50}{21}\\ 7,5x=\dfrac{3150}{525}\\ 7,5x=\dfrac{207}{35}\\ \dfrac{15}{2}x=\dfrac{207}{35}\\ x=\dfrac{207}{35}:\dfrac{15}{2}\\ x=\dfrac{207}{35}.\dfrac{2}{15}\\ x=\dfrac{414}{525}\\ x=\dfrac{138}{175}\)
\(7,5x:\left(9-\frac{139}{21}\right)=\frac{63}{25}\)
\(7,5x:\left(\frac{189}{21}-\frac{139}{21}\right)=\frac{63}{25}\)
\(7,5x:\left(\frac{50}{21}\right)=\frac{63}{25}\)
\(7,5x=\frac{63}{25}.\frac{50}{21}\)
\(7,5x=6\)
\(x=6:7,5\)
\(x=\frac{4}{5}\)
vậy \(x=\frac{4}{5}\)
k mk nha vì mk đang âm điểm
7,5x . 519 = 5 20 . 511
7,5x . 519 = 531
7,5x =531:519
7,5x=512