First, reduce the fraction:
#6/10=(p-7)/(p+10)#
#color(Red)cancelcolor(Black)6^3/color(red)cancelcolor(black)10^5=(p-7)/(p+10)#
#3/5=(p-7)/(p+10)#
Cross-multiply:
#3(p+10)=5(p-7)#
Use the distributive property:
#3*p+3*10=5*p-5*7#
#3p+30=5p-35#
#3p+30color(blue)+color(blue)35=5p-35color(blue)+color(blue)35#
#3p+30color(blue)+color(blue)35=5pcolor(red)cancelcolor(black)(color(black)-35color(blue)+color(blue)35)#
#3p+30color(blue)+color(blue)35=5p#
#3p+65=5p#
#3p+65color(blue)-color(blue)(3p)=5pcolor(blue)-color(blue)(3p)#
#color(red)cancelcolor(black)(3p)+65color(red)cancelcolor(blue)(color(blue)-color(blue)(3p))=5pcolor(blue)-color(blue)(3p)#
#65=5pcolor(blue)-color(blue)(3p)#
#65=2p#
#color(blue)(color(black)65/2)=color(blue)(color(black)(2p)/2)#
#color(blue)(color(black)65/2)=color(blue)(color(black)(color(red)cancelcolor(black)2p)/color(red)cancelcolor(blue)2)#
#color(blue)(color(black)65/2)=p#
This is the solution. Hope this helped!