If it's not what You are looking for type in the equation solver your own equation and let us solve it.
Simplifying
-81r2 + 121 = 0
Reorder the terms:
121 + -81r2 = 0
Solving
121 + -81r2 = 0
Solving for variable 'r'.
Move all terms containing r to the left, all other terms to the right.
Add '-121' to each side of the equation.
121 + -121 + -81r2 = 0 + -121
Combine like terms: 121 + -121 = 0
0 + -81r2 = 0 + -121
-81r2 = 0 + -121
Combine like terms: 0 + -121 = -121
-81r2 = -121
Divide each side by '-81'.
r2 = 1.49382716
Simplifying
r2 = 1.49382716
Take the square root of each side:
r = {-1.222222222, 1.222222222}
| -5x-4-1=3 | | -81r^2-121=0 | | 3x+2(4)=-7 | | 2.2=x-1.1 | | 92=5x+8(2-3x) | | f(3)=2x^3-7x^2+5x-1 | | 1x+-2(1x+6)=-1x+12 | | -n=(-4)-(-4n)+6 | | 2tan(x)=2 | | 900=-9(-9x-37) | | 7x+5=2(4+3) | | 4(x-3)=3x+2+x | | -2x+4=-15 | | 3m^2-18m-120=0 | | 2(-5+-3y)+2y=6 | | 3/4x-5/6y=-4 | | Ln2/5x^5y | | 4(x+1)-2x=0 | | 8(y+3)=96 | | 100=-80-11x+x^2 | | -5/8y=-13/14 | | 85=5(u+9) | | -9(y-3)=7-8y | | 4/-208 | | 6w-7=16 | | 3(x+3)=45 | | -2(x^2-1)=0 | | 516.5=13.5+10c | | -6n+21=12b-15 | | 250=25n | | 2(u-74)+39=75 | | -114=r-6(3r+2) |