a) \(-x+80=-220-5x\)

\(\Rightarrow-x+5x=-220-80\)

\(\Rightarrow4x=-300\)

\(\Rightarrow x=-\dfrac{300}{4}\)

\(\Rightarrow x=-75\)

b) \(98+\left(x-12\right)+68=-80-x\)

\(\Rightarrow166+\left(x-12\right)=-80-x\)

\(\Rightarrow166+x-12=-80-x\)

\(\Rightarrow154+x=-80-x\)

\(\Rightarrow154+80=-x-x\)

\(\Rightarrow-2x=234\)

\(\Rightarrow x=-\dfrac{234}{2}\)

\(\Rightarrow x=-117\)

c) \(122+x-78=-55-4x-1\)

\(\Rightarrow44+x=-56-4x\)

\(\Rightarrow x+4x=-56-44\)

\(\Rightarrow5x=-100\)

\(\Rightarrow x=-\dfrac{100}{5}\)

\(\Rightarrow x=-20\)

d) \(663+9x=-x-37\)

\(\Rightarrow9x+x=-37-663\)

\(\Rightarrow10x=-700\)

\(\Rightarrow x=-\dfrac{700}{10}\)

\(\Rightarrow x=-70\)

a) \(-\left(-a+c-d\right)-\left(c-a+d\right)\)

\(=a-c+d-c+a-d\)

\(=2a-2c\)

b) \(-\left(a+b-c+d\right)+\left(a-b-c-d\right)\)

\(=-a-b+c-d+a-b-c-d\)

\(=-2b-2d\)

c) \(a\left(b-c-d\right)-a\left(b+c-d\right)\)

\(=ab-ac-ad-ab-ac+ad\)

\(=-2ac\)

d) \(\left(a-b\right)+\left(c-d\right)+\left(a+c\right)-\left(b+d\right)\)

\(=a-b+c-d+a+c-b-d\)

\(=2a-2b+2c-2d\)

4: =4+5+{12+(-8)-(-8)-(-5)+(-12)+16-5+3}

=9+[12+5-12+16-5+3}

=9+19=28

5: =15-[13+8-10-16]-{5-7+9-3}

=15-(-5)-4

=15+5-4

=20-4

=16

g: =(32-34)+(36-38)+(40-42)

=(-2)+(-2)+(-2)

=-6

l: =-5-{-[7-10]-[5+12]}-[-3+9-4-5]

=-5+(-3)+17-[-3]

=-8+17+3

=20-8=12

\(p,71\cdot70+35\cdot\left(-7\right)-13\cdot35\)

\(=4970+\left(-245\right)-455=4725-455=4270\)

\(q,18\cdot\left(23-17\right)-13\cdot\left(23+18\right)\)

\(=18\cdot6-13\cdot41=108-533=-425\)

m) 63.83-9.7.(-17)

= 5229-63.(-17)

= 5229 - (-1071)

= 5229 + 1071

= 6300

n) 42.3 - 7[(-34)+18]

= 126 - 7. (-16)

= 126 - (-112)

=126+112

= 238

9: =>x-2/3=1/5*-7/15=-7/75

=>x=-7/75+50/75=43/75

11: =>x-4/5=3/10*(-7)/3=-7/10

=>x=-7/10+4/5=8/10-7/10=1/10

12:=>7/5*9+x=4/9

=>x=4/9-63/5=-547/45

10: =>x+5/6=-8/147

=>x=-87/98

\(1,-\dfrac{5}{12}\left(\dfrac{4}{9}+-\dfrac{5}{16}\right)\\ =-\dfrac{5}{12}\left(\dfrac{64}{144}+-\dfrac{45}{144}\right)\\ =-\dfrac{5}{12}.\dfrac{19}{144}\\ =-\dfrac{95}{1728}\\ 2,\left(-0,75+\dfrac{1}{2}\right)\left(\dfrac{1}{3}-\dfrac{1}{4}\right)\\ =\left(-\dfrac{3}{4}+\dfrac{1}{2}\right)\left(\dfrac{4}{12}-\dfrac{3}{12}\right)\\ =\left(-\dfrac{3}{4}+\dfrac{2}{4}\right).\dfrac{1}{12}\\ =-\dfrac{1}{4}.\dfrac{1}{12}\\ =-\dfrac{1}{48}\\ 3,-\dfrac{5}{7}.\dfrac{4}{13}+-\dfrac{5}{7}.\dfrac{9}{13}+-\dfrac{5}{7}\\ =-\dfrac{5}{7}.\dfrac{4}{13}+-\dfrac{5}{7}.\dfrac{9}{13}+-\dfrac{5}{7}.1=-\dfrac{5}{7}\left(\dfrac{4}{13}+\dfrac{9}{13}+1\right)\\ =-\dfrac{5}{7}\left(\dfrac{4}{13}+\dfrac{9}{13}+\dfrac{13}{13}\right)\\ =-\dfrac{5}{7}.\dfrac{26}{13}\\ =-\dfrac{5}{7}.2\\ =-\dfrac{10}{7}\)

\(b,4\dfrac{1}{2}x-\dfrac{1}{2}x=\dfrac{2}{3}:\dfrac{4}{9}\\ \dfrac{9}{2}x-\dfrac{1}{2}x=\dfrac{3}{2}\\ \left(\dfrac{9}{2}-\dfrac{1}{2}\right)x=\dfrac{3}{2}\\ 4x=\dfrac{3}{2}\\ x=\dfrac{3}{2}:4\\ x=\dfrac{3}{8}\)