If it's not what You are looking for type in the equation solver your own equation and let us solve it.
-21=-3p
We move all terms to the left:
-21-(-3p)=0
We get rid of parentheses
3p-21=0
We move all terms containing p to the left, all other terms to the right
3p=21
p=21/3
p=7
| r÷1.2+7.5=45 | | 228=3h | | (x*4)-x=1 | | 28=5u+8 | | 16-4=-30-3m | | (x*5)-x=1 | | 2.46j-15=-12.54 | | 6x–9=9+6x | | 72=6/10x | | 4x+5=12x+30 | | (x*3)-x=1 | | k2 + 7.3 = 29.3 | | -2x+18=-54 | | -3(u+5)=-45 | | x=11=-26 | | 13/4+c=3/4 | | 9r÷12=6 | | x/23=-29 | | 2^n=2048 | | -23=-6x+10 | | -1.2=-0.8r= | | 17+(-5)=-3x | | 2k–5=5 | | 4/x=1+1.4 | | -3x+10=4x+20 | | 12=x/14 | | -0(1-7r)=-18 | | r/17=-22 | | -5g=13g=54 | | Y=6.5x-5 | | -d/2=3/8= | | -17=m/17 |