Question

A: 502° CB: 6, 681° CC: 6, 135°CD: 47° C

Answer 1

The idea behind the problem is solving an equation involving square roots. The equation I'm talking about is

$358=20\cdot\sqrt[]{273+t}$

(I merely replaced v by 358; what we are supposed to do is to find t). Let's solve it:

1. 20 is multiplying at the right-hand side, let's send it to divide at the left:

$\frac{358}{20}=\sqrt[]{273+t}$

2. (this is the most important step) Take the power of 2 on both sides:

$(\frac{358}{20})^2=273+t$

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Comment: Remember that

$(\sqrt[]{273+t})^2=273+t$

because square root and powering by two are inverse of each other.

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3. Put the left-hand side in a calculator to get:

$\frac{128164}{400}=273+t$

4. Let's subtract 273 to the left-hand side:

$320.41-273=t$$47.41\degree C=t$