Answer:

Step-by-step explanation:
First, we need to isolate
by taking it common from both terms on the right:

Now, since we want
in terms of the other variables, we can divide the left hand side (A) by whatever is multiplied with
on the right hand side. Then we will have an expression for
. Shown below:

This is the xpression for 
the question in English
Mateo will reproduce a photo measuring 5 cm per side on a scale of 3/4
How much will the square side of the copy measure?
Will the size of the copy be larger or smaller than the original?
we know that
the scale factor is equal to 
Let
x----------> the original length side
y--------> the copy length side

we have that

substitute the values

therefore
<u>the answer Part a) is </u>
the length side of the copy measure is 
Part b)
we know that
the size of the original photo is------> 
the size of the copy is------> 
so

therefore
<u>the answer part b) is</u>
The size of the copy be smaller than the original
Answer:
The Proof for
△ABD ≅ △CBD is below
Step-by-step explanation:
Given:


AD = CD .........BD bisect AC
To Prove:
△ABD ≅ △CBD
Proof:
In ΔABD and ΔCBD
BD ≅ BD ....……….{Reflexive Property}
∠ADB ≅ ∠CDB …………..{Measure of each angle is 90°(
)}
AD ≅ CD ....……….{
}
ΔABD ≅ ΔCBD .......….{By Side-Angle-Side Congruence test} ...Proved