\(\dfrac{4}{9}+\dfrac{16}{36}\)
\(x+\dfrac{4}{9}+\dfrac{8}{18}+\dfrac{12}{27}+\dfrac{16}{36}=\dfrac{16}{9}\)
giúp mk với ạ
x + 4/9 + 8/18 + 12/27 + 16/36 = 16/9
x + (4/9+12/27)+(8/12+16/36) = 16/9
x + 8/9 + 10/9 = 16/9
x + 2 = 16/9
x = 16/9 - 2
x = -2/18
x+4/9+4/9+4/9+4/9=16/9
x+4/9.4=16/9
x+16/9=16/9
--> x = 0
Câu 1: Thực hiện phép tính
a, \(\dfrac{7}{9}-\dfrac{16}{9}\)
b, \(\dfrac{2}{-15}+\dfrac{7}{10}\)
c, \(\left(4\dfrac{2}{3}-4\dfrac{3}{4}\right):\dfrac{-5}{12}-\dfrac{4}{5}\)
d, \(\dfrac{-141}{157}.\dfrac{23}{59}-\dfrac{141}{157}.\dfrac{36}{59}+\dfrac{16}{-157}\)
a. 7/9 - 16/9 = -9/9 = -1
b. 2/-15 + 7/10 = 17/30
c. (4 2/3 - 4 3/4) : -5/12 - 4/5
= (14/3 - 19/4) : (-5/12) - 4/5
= -1/12 : (-5/12) - 4/5
= 1/5 - 4/5
= -3/5
Tính: \(A=\dfrac{3}{4}.\dfrac{8}{9}.\dfrac{15}{16}.\dfrac{24}{25}.\dfrac{35}{36}.\dfrac{48}{49}.\dfrac{63}{64}\)
thực hiện phép tính
\(\dfrac{16}{103}\)+(38+\(\dfrac{-16}{103}\))
\(\dfrac{100}{91}\)+310+\(\dfrac{-9}{91}\)
\(\dfrac{-13}{49}\)+(\(\dfrac{-36}{49}\)+41)
\(\dfrac{-10}{71}\):1\(\dfrac{4}{71}\)
\(\dfrac{4}{15}\)+\(\dfrac{8}{15}\):2 -\(\dfrac{1}{18}\).\(\left(-3\right)^2\)
`16/803+38+(-16/803)`
`=16/803-16/803+38`
`=0+38=38`
`100/91+310-9/91`
`=100/91-9/91+310`
`=1+310=311`
\(\dfrac{16}{103}+\left(38+\dfrac{-16}{103}\right)\)
\(=\dfrac{16}{103}+38+\dfrac{-16}{103}\)
\(=\dfrac{16}{103}+\dfrac{-16}{103}+38\)
\(=0+38\)
\(=38\)
A = \(\dfrac{1}{2}+\dfrac{4}{5}+\dfrac{9}{10}+\dfrac{16}{17}+\dfrac{25}{26}+\dfrac{36}{37}\) hỏi a = bao nhiêu
do dịch covid mình quên dạng này rồi ://
A=5,07568791
Vì NY mk bảo giúp bạn nên mk mới giúp đấy.
khoanh vào phân số bằng \(\dfrac{4}{9}\) \(\dfrac{12}{18}\), \(\dfrac{6}{10}\), \(\dfrac{16}{27}\), \(\dfrac{24}{54}\), \(\dfrac{20}{36}\)
các phân số bằng \(\dfrac{4}{9}\)là
\(\dfrac{24}{54}\)
Điền số thích hợp vào ô vuông:
a) \(\dfrac{1}{2}\)=\(\dfrac{ }{12}\) b)\(\dfrac{ }{8}\)=\(\dfrac{-28}{32}\) c)\(\dfrac{3}{4}\)=\(\dfrac{ }{20}\)
d)\(\dfrac{ }{9}\)=\(\dfrac{-16}{36}\) e)\(\dfrac{3}{4}\)=\(\dfrac{15}{ }\)
a) \(\dfrac{1}{2}\)=\(\dfrac{6}{12}\) b) \(\dfrac{-7}{8}\)=\(\dfrac{-28}{32}\) c)\(\dfrac{3}{4}\)=\(\dfrac{15}{20}\) d) \(\dfrac{-4}{9}\)=\(\dfrac{-16}{36}\)
e) \(\dfrac{3}{4}\)=\(\dfrac{15}{20}\)
HỌC TỐT
thực hiện phép tính
\(\dfrac{x}{x-3}-\dfrac{6}{x}-\dfrac{9}{x^2-3x}\)
\(\dfrac{7}{x}-\dfrac{x}{x+6}+\dfrac{36}{x^2+6x}\)
\(\dfrac{6}{x-3}-\dfrac{2x-16}{x^2-9}-\dfrac{4}{x+3}\)
a) Ta có: \(\dfrac{x}{x-3}-\dfrac{6}{x}-\dfrac{9}{x^2-3x}\)
\(=\dfrac{x^2}{x\left(x-3\right)}-\dfrac{6\left(x-3\right)}{x\left(x-3\right)}-\dfrac{9}{x\left(x-3\right)}\)
\(=\dfrac{x^2-6x+18-9}{x\left(x-3\right)}\)
\(=\dfrac{\left(x-3\right)^2}{x\left(x-3\right)}=\dfrac{x-3}{x}\)
b) Ta có: \(\dfrac{7}{x}-\dfrac{x}{x+6}+\dfrac{36}{x^2+6x}\)
\(=\dfrac{7\left(x+6\right)-x^2+36}{x\left(x+6\right)}\)
\(=\dfrac{7x+42-x^2+36}{x\left(x+6\right)}\)
\(=\dfrac{-\left(x^2-7x-78\right)}{x\left(x+6\right)}\)
\(=\dfrac{-\left(x^2-13x+6x-78\right)}{x\left(x+6\right)}\)
\(=\dfrac{-\left[x\left(x-13\right)+6\left(x-13\right)\right]}{x\left(x+6\right)}\)
\(=\dfrac{13-x}{x}\)
c) Ta có: \(\dfrac{6}{x-3}-\dfrac{2x-6}{x^2-9}-\dfrac{4}{x+3}\)
\(=\dfrac{6\left(x+3\right)-2x+6-4\left(x-3\right)}{\left(x-3\right)\left(x+3\right)}\)
\(=\dfrac{6x+18-2x+6-4x+12}{\left(x-3\right)\left(x+3\right)}=\dfrac{36}{\left(x-3\right)\left(x+3\right)}\)
Câu 1 :\(\dfrac{-5}{7}.\dfrac{7}{-45}\);\(\dfrac{-3}{10}.\left(-30\right)\);\(-12.\dfrac{-2}{36}\)
Câu 2: \(\dfrac{3}{4}+\dfrac{1}{8}.\dfrac{-16}{5};\dfrac{7}{15}-\dfrac{18}{21}.\dfrac{7}{9}\)
Câu 3: \(\left(\dfrac{-5}{9}+\dfrac{3}{5}\right).\dfrac{3}{10};\left(\dfrac{3}{9}-\dfrac{2}{5}\right).\dfrac{-3}{10}\)
Câu 4: \(\left(\dfrac{3}{7}+\dfrac{1}{3}\right).\left(\dfrac{1}{8}-\dfrac{1}{2}\right);\left(\dfrac{-9}{12}-\dfrac{16}{30}\right).\left(\dfrac{-18}{22}-\dfrac{6}{11}\right)\)
Càn gấp
Câu 1:
\(-\dfrac{5}{7}\cdot\dfrac{7}{-45}=\dfrac{1}{9}\) ; \(-\dfrac{3}{10}\cdot-30=9\) ; \(-12\cdot-\dfrac{2}{36}=\dfrac{2}{3}\)
Caau2;3;4;5,... tự bấm máy tính là ra