If it's not what You are looking for type in the equation solver your own equation and let us solve it.
78=2r
We move all terms to the left:
78-(2r)=0
We move all terms containing r to the left, all other terms to the right
-2r=-78
r=-78/-2
r=+39
| a-⅚=-3⅔ | | -4.1=7.1+v/7 | | 13x-3+9x+4=90 | | x+6=2x2 | | 2x+8=23-x | | y-45=89y | | 3(x-8)=-2(x-3)+5 | | 4x+7=10-x | | Y=100(.25)x | | 3.2k=40 | | h+11.5=11.5 | | 208=105-v | | 3x+7=6x+7−3x. | | ⅔k=28 | | 60+3x=105 | | 3x+15+3x-22+2x+1=180 | | 78x-624=2964 | | 7(3x-4)=11(2x+5) | | w+112=4 | | x+85=6x+65 | | 4x+7x+8x=152 | | ⅔k=28 | | -4(6.4x-9)=-3(7.2x+4) | | 3+5x+2=-35 | | 2x+80+100+2x=180 | | z+23=167 | | (6x+40)+2x^2=180 | | 135=-5(-3+5x) | | Y=9/4x+1 | | -5x+1=1-5 | | 4x–1=7x+2 | | 2(x+3)=50* |