If it's not what You are looking for type in the equation solver your own equation and let us solve it.
Simplifying
4r2 + -9 = 91
Reorder the terms:
-9 + 4r2 = 91
Solving
-9 + 4r2 = 91
Solving for variable 'r'.
Move all terms containing r to the left, all other terms to the right.
Add '9' to each side of the equation.
-9 + 9 + 4r2 = 91 + 9
Combine like terms: -9 + 9 = 0
0 + 4r2 = 91 + 9
4r2 = 91 + 9
Combine like terms: 91 + 9 = 100
4r2 = 100
Divide each side by '4'.
r2 = 25
Simplifying
r2 = 25
Take the square root of each side:
r = {-5, 5}
| X^5-81x^3-44590=0 | | 8y+2(0)=80 | | (6/2x+12)+(6/x+6)+(6/x)=1 | | (-3/2)+(1/3)x=2+(5/6)x | | 2(1+16x)=2 | | -32h^3+80h^2y-50hy^2=0 | | -4(x)=-3x-6 | | 6x-3=1+6 | | 14-10x=54-45x | | -3.5(x)=-3x-6 | | -4x+1=3x-48 | | 0+2y=80 | | 4a^2-12at+9t^2=0 | | -2.9x-2.24=-17.9 | | 3q-16q=7+(-8q-3) | | 6x^2+146x+468=2x^3 | | 2(x)=-3x-6 | | s(x)=0.5x^2-4x+9 | | 12.4+3.7x=2.04 | | (3^2*5^3/27x)^2 | | 23+1/5k-7=23 | | 4y-20=4y-20 | | x^2-1.8x+0.81=0 | | 9a+3+4a=51+5a | | (1/2)+4x=3x-(5/2) | | n/3+10=11 | | 20-8n+7=3 | | N/3 | | 4+5y=10y-1 | | 20x+5=40+9x-2 | | 14=30-x | | 4+5y=10y-16 |