a.)
`a/5+b/5=color(red)((a+b)/5)`

d.)
`(3x-2)/5+(2x+3)/3=(3*(3x-2)+5*(2x+3))/15=(9x-6+10x+15)/15=color(red)((19x+9)/15)`

f.)
`(2c+7)/a-7/a=(2c+7-7)/a=color(red)((2c)/a)`

h.)
`(5a+2b)/(8b)-(5a-3b)/(8b)=(5a+2b-(5a-3b))/(8b)=(5b)/(8b)=color(red)(5/8)`

j.)
`(a+b)/(a+x)-(a+2b)/(b-a)=((b-a)*(a+b)-(a+x)*(a+2b))/((a+x)*(b-a))=color(red)((b^2-2a^2-2ab-ax-2bx)/(ab-a^2+bx-ax))`

l.)
`(a+b)/(a-b)-(a+2b)/(b-a)=(a+b)/(a-b)+(a+2b)/(a-b)=(a+b+a+2b)/(a-b)=color(red)((2a+3b)/(a-b)`

n.)
`x/(ab)+x/(ac)=(cx)/(abc)+(bx)/(abc)=color(red)((cx+bx)/(abc))`

o.)
`(5x)/(ab)+(2y)/(3a^2b)-3/(6a^2y^2)=color(red)((30axy^2+4y^3-3b)/(6a^2by^2))`

q.)
`(2a-3b)/(a^2b)-(4a-5b)/(ab^2)=(b*(2a-3b)-a*(4a)-5b)/(a^2b^2)=color(red)((7ab-3b^2-4a^2)/(a^2b^2))`

s.)
`2a-(a-b)/5=(10a-(a-b))/5=color(red)((9a+b)/5)`

t.)
`3/(a-1)+2/a=(3a+2*(a-1))/(a*(a-1))=color(red)((5a-2)/(a^2-a))`