Answer:
x = 12
Step-by-step explanation:
Step 1: Define
f(x) = 4x + 6
f(x) = 54
Step 2: Substitute variables
54 = 4x + 6
Step 3: Solve for <em>x</em>
<u>Subtract 6 on both sides:</u> 48 = 4x
<u>Divide both sides by 4:</u> 12 = x
Step 4: Check
<em>Plug in x to verify it is a solution.</em>
f(12) = 4(12) + 6
f(12) = 48 + 6
f(12) = 54
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Using the formula of a triangle A=1/2BH, the answer is 49
The rink has a dimension of 200 ft* 85 ft = 17000 
depth = 1.5 inch that becomes
= 0.125 ft
So total volume of the water required = 17000* 0.125 = 2125 
Now 1 cubic foot of water= 7.480 gallons
Hence total gallons required are 2125 * 7.480 gallons = 15895 gallons.