Please show your work! I have 3 more of these, and I want to be able to do them by myself.

Step-by-step explanation:

We group the number 5:

5(x² + 3x + 2.25)

Now inside the brackets we'll take the square root of the coefficient of the x and the square root of the last number, then remove the square from the x and write it as a sum:

5(x+1.5)²

What's the idea behind this?

Well, remember that when you have something in the form:

(a+b)²

It actually means:

a² + 2ab + b²

In our case a was x, and b was 2.25. For bringing it into the shorter form we have to take the square root of a and b.

Sorry if you don't understand. Tell me if you need help to get the xoncept better.

d. bc = 12 and ef = 16

step-by-step explanation:

we are given that δabc : δdef such that .

also, it is given that

so, from the options, we need that .

a.

b.

c.  

d.

as, we can see that only option d gives the same ratio as i.e. .

hence, the possible lengths are bc = 12 and ef = 16.

f(x) = - 2/3x + 5; f(5/2)

substitute 5/2 in for x:

f(5/2) = -2/3(5/2) + 5

simplify the right side:

f(5/2) = -5/3 + 5

f(5/2) = 10/3

answer:

f(5/2) = 10/3

i hope this you!