91Ó°ÊÓ

Real numbers are simply the combination of Whole numbers, Integers, Rational and Irrational numbers in the number system.

Multiplication Properties of Real numbers:

Suppose a, b, and c is three real numbers.

Closure Property of Multiplication

Property: $\text{a}  ·  b$ is a real number.

If we multiply two real numbers, then their product is also a real number.

Example: $\text{8}  ·  9  =72$, where 72 (the product of 8 and 9) is a real number.

Given in the question:

3 boxes of spaghetti = $1.19$each

$4$ Jars of spaghetti sauce = $2.39$ each

Cost of one box of spaghetti = $1.19$

Cost of $3$ boxes of spaghetti = $3  ·  1.19=3.57$

Cost of one jar of spaghetti sauce = $2.39$

Cost of $4$ jars of spaghetti sauce = $4  ·  2.39=9.56$

Total cost of 3 boxes of spaghetti and 4 jars of spaghetti sauce = $3.57+9.56=13.13$