Combine like terms such that each variable only appears once.
$0.5z+.25z-1.35+1.55$

• A. $0.75z-0.2$
• B. $0.75z+0.2$
• C. $0.95z$
• D. $-2.15z$

Answer: (B)

Verified step by step guidance

1. Identify the like terms in the expression. Like terms are terms that have the same variable raised to the same power. Here, the terms with the variable \( z \) are \( 0.5z \) and \( 0.25z \), and the constant terms are \( -1.35 \) and \( +1.55 \).
2. Combine the coefficients of the like terms with the variable \( z \). This means adding \( 0.5 \) and \( 0.25 \) together while keeping the variable \( z \) unchanged, resulting in \( (0.5 + 0.25)z \).
3. Combine the constant terms by adding \( -1.35 \) and \( +1.55 \) together to simplify the constant part of the expression.
4. Write the simplified expression by putting together the combined \( z \)-term and the combined constant term, resulting in an expression of the form \( az + b \), where \( a \) and \( b \) are the sums you found.
5. Double-check your work by ensuring that each variable appears only once and that all constants are combined correctly, confirming the expression is fully simplified.