which expression is equivalent to -3x + 5.1? a -3(x + 1.7) b -3(x - 1.7) c 3(x + 1.7) d 3(x - 1.7)
which expression is equivalent to -3x + 5.1? a -3(x + 1.7) b -3(x - 1.7) c 3(x + 1.7) d 3(x - 1.7)
Answer
Explanation:
Step1: Expand each option
- Option A: $$ \begin{align*} -3(x + 1.7)&=-3\times x+(-3)\times1.7\ &=-3x-5.1 \end{align*} $$
- Option B: $$ \begin{align*} -3(x - 1.7)&=-3\times x-3\times(-1.7)\ &=-3x + 5.1 \end{align*} $$
- Option C: $$ \begin{align*} 3(x + 1.7)&=3\times x+3\times1.7\ &=3x + 5.1 \end{align*} $$
- Option D: $$ \begin{align*} 3(x - 1.7)&=3\times x+3\times(-1.7)\ &=3x-5.1 \end{align*} $$
Answer:
B. $-3(x - 1.7)$