a) \(-12\left(x-5\right)+7\left(3-x\right)=5\)

\(-12x+60+21-7x=5\)

\(-19x=5-60-21\)

\(-19x=-76\)

\(x=4\)

vậy \(x=4\)

tương tự 

A, 5+ ( -12 ) - 10 = -17

B, 25 - (-17) + 24 -12=54

C, 5^6  : 5^4 + 2^3 . 2^2 -225 : 15^2 =56

D, ( -5 - 3). (3 -5 ) : ( -3 + 5)=8

E,4. (13-16) -(3-5).(-3^2) =15

F, 235 - (34 + 135)-100=-34

a; (4 - \(\dfrac{12}{5}\)).\(\dfrac{25}{8}\) - \(\dfrac{2}{5}\) : - \(\dfrac{4}{25}\)

= 4.\(\dfrac{25}{8}\) - \(\dfrac{12}{5}\).\(\dfrac{25}{8}\) - \(\dfrac{2}{5}\) x \(\dfrac{-25}{4}\)

= \(\dfrac{25}{2}\) - \(\dfrac{15}{2}\) + \(\dfrac{5}{2}\)

= \(\dfrac{10}{2}\) + \(\dfrac{5}{2}\)

 = \(\dfrac{15}{2}\) 

b; (- \(\dfrac{5}{24}\) + \(\dfrac{3}{4}\) - \(\dfrac{7}{12}\)) : (- \(\dfrac{5}{16}\))

 = (- \(\dfrac{5}{24}\)) : (-\(\dfrac{5}{16}\)) + \(\dfrac{3}{4}\) : (- \(\dfrac{5}{16}\)) - \(\dfrac{7}{12}\) : (- \(\dfrac{5}{16}\))

= \(\dfrac{5}{24}\) x \(\dfrac{16}{5}\) - \(\dfrac{3}{4}\) x \(\dfrac{16}{5}\) + \(\dfrac{7}{12}\) x \(\dfrac{16}{5}\) 

= \(\dfrac{2}{3}\) - \(\dfrac{12}{5}\) + \(\dfrac{28}{15}\)

= \(\dfrac{10}{15}\) - \(\dfrac{36}{15}\) + \(\dfrac{28}{15}\)

= \(\dfrac{-26}{15}\) + \(\dfrac{28}{15}\)

 = \(\dfrac{2}{15}\)