Because if you multiply 2 different irrational numbers (like the following)

You will get an irrational answer.
BUT
if you multiply the same square root (which are both irrational, you get a rational number)
Step-by-step explanation:
Rate of drop of temperature = Change in temperature/Rate
=> (165 - 135)/15
=> 30/15
=> 2 ⁰F/min
Now, The time at which the temperature of will be 70⁰F = 70/Rate
=> 70/2
=> 35 min
Time for 110⁰ F
=> 110/2
=> 55 min
Step-by-step explanation:
Standard form is ax^2 + bx + c. Vertex form is a(x-h)^2 + k, which reveals the vertex and axis of symmetry. Factored form is a(x-r)(x-s), which reveals the roots.