1. 4
2. 9
3. 21
are the answers
If we let p and t be the masses of the paper and textbook, respectively, the equations that would best represent the given in this item are:
(1) 20p + 9t = 44.4
(2) (20 + 5)p + (9 + 1)t = 51
The values of p and t from the equation are 0.6 and 3.6, respectively. Thus, each paperback weighs 0.6 pounds and each textbook weighs 3.6 pounds.
Answer:
<em><u>Lines are perpendicular to each other .</u></em>
Step-by-step explanation:
Standard equation of line is : y = mx + c, Where m represents the slope
Given Equations :


Two lines are parallel if the slope of the lines are same.
Two line are perpendicular if the product of the slope = - 1
Clearly slopes are not equal , therefore the lines are not parallel.
product of the slope is - 1, therefore the lines are perpendicular.

Red blood cell, as they have a biconcave shape and need to store a lot of haemoglobin, the pigment of blood
hope this helps! :)