Hey there!
Tom's age to Mary's is 3:4; an equivalent ratio is 15:x (x symbolizes Mary's age).
To solve for this, we need to divide our proportions. By that, I mean divide Tom's older age by his younger age. If we do so, we should get a scale factor that we can multiply Mary's younger age by.
15 / 3 = 5
This means that the scale factor of the ages is 5.
x / 4 = 5 (Solving for Mary's unknown age.)
To solve for x, multiply both sides by 4.
x/4 * 4 = x
5 * 4 = 20
x = 20
Mary's age is 20.
I hope this helps!
To answer this question we will have to understand the nature of 
.
can be rewritten as: 
. Now, 
is an irrational number and thus any of the four operations of addition, multiplication, subtraction or division placed anywhere between any of these terms will always result in an irrational number.
The only way irrational numbers can be made rational is by dividing or multiplying the given irrational number by the same irrational number.
x = 4.5 so it is 3/-8 = 4.5/12
The angles are <span>supplementary
</span>
7x + x + 20 = 180
8x = 160
x = 20
