The sum of two number is 15 and thir is 1 difference

Number first = 8

Number second = 7

Explanation:

Given:

Sum of two number = 15

Difference of two number = 1

Assume;

Number first = x

Number second = y

Computation:

x + y = 15eq1

x - y = 1eq2

eq1 - eq2

So,

2x = 16

x = 8

Number first = 8

x + y = 15

8 + y = 15

y = 7

Number second = 7

The correct answer is B: Greeks.

Explanation:

In the 6th century BC, the Ancient Greeks began with their systematic studies of mathematics. One of the first world mathematicians was Thales of Miletus, and the discovery of mathematics has been attributed to him.

One of the first systematical studies was realized by an ancient mathematician Pythagoras, who questioned the basic understanding of triangles, today known as the Pythagorean Theorem.

However, a Greek mathematician, Archimedes, is considered to be the father of mathematics.