Answer:
The value of variable r in the equation
is 
Step-by-step explanation:
We need to find the value of variable r in the equation 
Step 1: Write the equation

Step 2: Subtract 4 on both sides

Step 3: Divide both sides by 4

So, The value of variable r in the equation
is 
15 volume of the fish tank
What type of math is this?
No. Solve each of the problems and see if they match. Do PEMDAS order of operations
Step-by-step explanation:
5(tanx)^2 -2 +tanx=0
let tanx=y
5y^2 + y-2=0
y=0.5403 or y= -0.7403
tanx=0.5403
x=arctan(0.5403)
x=28.38°
or
tanx=-0.7403
x=arctan(-0.7403)
x=143.49°