`a)5/9:(1/11-5/22)+5/9:(1/15-2/3)`

`=5/9:(2/22-5/22)+5/9:(1/15-10/15)`

`=5/9:(-3)/22+5/9:(-9)/15`

`=5/9*(-22)/3+5/9*(-5)/3`

`=5/9*(-22/3+(-5)/3)`

`=5/9*(-9)=-5`

\(\left(-\frac{15}{22}\div-\frac{5}{11}\right)\cdot\frac{2}{3}\)

\(=\left(-\frac{15}{22}\cdot-\frac{11}{5}\right)\cdot\frac{2}{3}\)

\(=-\frac{3}{2}\cdot\frac{2}{3}\)

\(=-1\)

(-15/22: -5/11). 2/3

= ( -15 /22 x -11 / 5 ) x 2/3

=        3/2            x  2/3 

=             6/6

=            1

=(-15/22.-11/5).2/3

=3/2.2/3

=6/6=1
 

d: \(\dfrac{1}{27}:\left(-\dfrac{1}{3}\right)^2+75\%\cdot\left(-\dfrac{2^2}{3}\right)\)

\(=\dfrac{1}{27}:\dfrac{1}{9}+\dfrac{3}{4}\cdot\dfrac{-4}{3}\)

\(=\dfrac{1}{3}-1\)

\(=-\dfrac{2}{3}\)

a, (x+1)×(y+3)=5

=> x+1 và y+3 \(\in\) Ư(5) = {-1;-5;1;5}

ta có bảng sau :

vậy các cặp số (x;y) thỏa mãn là : (-2; -8); (-6; -4); (0; 2); (4; -2)

b, ko bt làm!

c, x² + xy + y = 22

=> x.x + xy + y = 22

=> x(x+y) + x + y = 22 + y

=> x(x+y) + 1(x+y) = 22 + y

bí ròi

11 + 11 = 22

66 + 66 = 132

33 + 33 = 66

~ hok tốt ~

11+11=22

66+66=132

33+33=66

hok tốt

11+11=22

66+66=132

33+33=66

a)\(\left(\frac{3}{4}+\frac{-7}{2}\right).\left(\frac{10}{11}+\frac{2}{22}\right)\)

\(\left(\frac{3}{4}+\frac{-14}{4}\right).\left(\frac{20}{22}+\frac{2}{22}\right)\)

\(\frac{-11}{4}.1=\frac{-11}{4}\)

câu b mk hiểu đề

0,75+7/12 chứ không phải = đâu