explain pls and thanks

Solve for x:
(2 x)/5+7 = x/4-7/2

Put each term in (2 x)/5+7 over the common denominator 5: (2 x)/5+7  =  (2 x)/5+35/5:
(2 x)/5+35/5 = x/4-7/2

(2 x)/5+35/5 = (2 x+35)/5:
(2 x+35)/5 = x/4-7/2

Put each term in x/4-7/2 over the common denominator 4: x/4-7/2  =  x/4-(14)/4:
(2 x+35)/5 = x/4-(14)/4

x/4-(14)/4 = (x-14)/4:
(2 x+35)/5 = (x-14)/4

Multiply both sides by 20:
(20 (2 x+35))/5 = (20 (x-14))/4

20/5 = (5×4)/5 = 4:
4 (2 x+35) = (20 (x-14))/4

20/4 = (4×5)/4 = 5:
Answer: | 4 (2 x+35) = 5 (x-14)     x=-70

[2/5]x+7=[1/4]x-[7/2]    multiply through by the common denominator of 2, 4, 5   = 20

8x  + 140  = 5x - 70   add 70 to both sides,     subtract 8x from both sides

210  = - 3x       divide both sides by -3

-70  = x