Chapter 8.2, Problem 90CCR

To determine

The solution of the expression $2z+2y$ ,

Answer to Problem 90CCR

The solution of the expression is $-12$ .

Explanation of Solution

Given:

The expression, $2z+2y$ .If $x=4,y=-10,\text{and z}=14$

Concept Used:

• To get rid of a number in addition from one side, subtract the same number from both sides of equal sign.
• To get rid of a number in subtraction from one side, add the same number both sides of equal sign.
• To get rid of a number in multiplication from one side, divide the same number from both sides of equal sign.
• To get rid of a number in division from one side, multiply the same number both sides of equal sign.

Rules of Addition/ Subtraction:

• Two numbers with similar sign always get added and the resulting number will carry the similar sign.
• Two numbers with opposite signs always get subtracted and the resulting number will carry the sign of larger number.

Rules of Multiplication/ Division:

• The product/quotient of two similar sign numbers is always positive.
• The product/quotient of two numbers with opposite signs is always negative.

Calculation:

In order to solve the given expression $2z+2y$ put the values $x=4,y=-10,\text{and z}=14$ in the given expression and then simplify further as shown below,

  $\begin{array}{c}2z+2y=2\times 4+2\left(-10\right)\\ =8-20\\ =-12\end{array}$

Thus, the solution of the expression is $-12$ .