Kareen has 2.56 pieces of led for her lead pencil. It fills up the entire pencil. How many pieces of led would she need for 20 pencils?(No caculators I will know if you use one and this requires a explanation)

Write the sentence as an equation. z plus 372 is equal to 160

Tim's phone service charges $23.06 plus an additional $0.22 for each text message sent per month. if tim's phone bill was $28.56, which equation could be used to find how many text messages, x, tim sent last month?

Which of the following is true for the relation f(x)=2x^2+1