Question

If u + t = 5 and u-t=2, what is the value of (u – t)(u² - 12) ?

Answer 1

Answer:

(u – t)(u² - 12) is equal to 0.5.

Step-by-step explanation:

First let's find u and t:

Given u + t = 5, and u - t = 2

We'll substitute one of those into the other equation.

Let's solve the second one for u:

u - t = 2

u = 2 + t

Now we can substitute that definition into the first equation:

u + t = 5

(2 + t) + t = 5

2 + 2t = 5

2t = 3

t = 1.5

Now we can substitute that into either of the original equations to find u:

u = 2 + t

u = 2 + 1.5

u = 3.5

So t = 1.5 and u = 3.5. Now we can substitute them into the given expression to solve it:

(u – t)(u² - 12)

= (3.5 – 1.5)(3.5² - 12)

= (3.5 – 1.5)(12.25 - 12)

= 2 × 0.25

= 0.5

Answer 2

Answer:

0.5

Step-by-step explanation:

You know that u-t is 2, so it'll be 2($u^{2}$ -12)

Now, system of equations to solve for u.  if u+t=5, this means t=5-u, you can plug it in into u-t=2, so u-(5-u)=2. Now you know that u is 3.5, so do the calculations.