a) -15x + 20 =-25

\(\Leftrightarrow\) -15x = -25 - 20 = -45

\(\Leftrightarrow\)x = 3

\(\frac{-63}{108}\)= \(\frac{-7}{12}\)

\(\frac{-33}{-77}\)= \(\frac{3}{7}\)

\(\frac{-5}{10}\)=\(\frac{-1}{2}\)

\(\frac{14}{63}\)=\(\frac{2}{9}\)

\(\frac{-15}{25}\)=\(\frac{-3}{5}\)

\(\frac{-45}{18}\)=\(\frac{-5}{2}\)

\(\frac{12}{15}\)=\(\frac{4}{5}\)

\(\frac{20}{25}\)=\(\frac{4}{5}\)

\(\frac{31}{12}\):Là phân số tối giản

t.i.c.k nha                                           

\(=\left(-67\right).\left(-33\right)-67.77+\left(-67\right).33-77.33\)

\(=\left[\left(-67\right).\left(-33\right)+\left(-67\right).33\right]-66.77-77.33\)

\(=-77\left(66+33\right)=-77.99=-7623\)

có thể là 25 số 154 

77⁵⁵có tận cùng là 3

33⁶có tận cùng là 9

nên 33⁶+77⁵-2 có tận cùng là 3+9-2=...0 chia hết cho 5

3+99+22+33+77+22x69x25-38-95=38051

k nha

441467 nha

cho minh

\(77^{33}=\left(11.7\right)^{33}=11^{33}.7^{33}=11^{33}.\left(7^3\right)^{11}=11^{33}.343\left(1\right)\)

\(33^{77}=\left(3.11\right)^{77}=3^{77}.11^{77}=\left(3^7\right)^{11}.11^{77}=2187^{11}.11^{77}\left(2\right)\)

Từ \(\left(1\right)+\left(2\right)\Leftrightarrow33^{77}>77^{33}\)

a: \(-177-\left\lbrack89+\left(-177\right)+75\right\rbrack-\left(-25\right)\)

=-177-[89-177+75]+25

=-177-89+177-75+25

=-89-50

=-139

b: \(2\cdot\left\lbrack16+\left(-12\right)-5\right\rbrack+\left(-32\right)-\left(-10\right)\)

\(=2\cdot\left\lbrack16-17\right\rbrack-32+10\)

=2*(-1)-32+10

=-34+10

=-24

c: \(56\cdot53-\left\lbrack57+\left(-75\right)-\left(-9\right)\cdot2\right\rbrack\)

=2968-[57-75+18]

=2968

d: \(16\cdot\left(-45\right)+16\cdot34-\left(-16\right)\cdot\left(-89\right)\)

\(=16\left(-45+34\right)-16\cdot89\)

\(=16\left(-11-89\right)=16\cdot\left(-100\right)=-1600\)

e: \(77\cdot18-\left(-77\right)\cdot60+\left(-77\right)\cdot\left(-22\right)\)

\(=77\cdot18+77\cdot60+77\cdot22\)

\(=77\left(18+60+22\right)=77\cdot100=7700\)