If it's not what You are looking for type in the equation solver your own equation and let us solve it.
12^(r-1)=7^r
We move all terms to the left:
12^(r-1)-(7^r)=0
| 6x-12=1/2(6+14x-(58)) | | 4082.1=15590x+338.36 | | 10(w+5=60 | | (x+7)2=3 | | 5x+20=2x+x+50 | | -2x+5-6+10=31-8x | | 7x-3-5x=18 | | 3(r+5)=15+3r | | 135=-10a-5 | | 16+y=88 | | -5x+23=5(4-x) | | -29+v=74 | | y-18=79 | | 4(q+5)=44 | | 6g=486g=486 | | –10−6c=–4c | | 1.5n+9=1.5n+6 | | 6–8p=38 | | x–7=13-x | | a÷5-8=1 | | –2w+–17=–39 | | 65=f−2 | | 46/57/5=360/q | | 75-7x=10 | | t−7=29 | | s+5=90 | | 〖9x〗^2-2x+3=0 | | 2(x-5)+7=5x+12 | | 12x=104+166 | | -20-9y=16 | | 89n-12=-12 | | 12x=52+166 |