Answer:
<BCD=105 Degrees
Step-by-step explanation:
To solve this problem, you need to use linear pairs
Linear pairs are two angles on the same line divided by a single line between them. Linear pairs will always add up to 180 as they are supplementary.
Therefore, 180-75 will give you x, which is 105
Let x be the mass of the paperbacks and y be the mass of the textbook.
20x + 9y = 44.4 ----------- (1)
25x + 10y = 51 -------------(2)
(1) x 10:
200x + 90y = 444 --------(1a)
(2) x 9:
225x + 90y = 459 --------(2a)
(2a) - (1a):
25x = 15
x = 0.6 -------- sub into (1)
20 (0.6) + 9y = 44.4
12 + 9y = 44.4
9y = 44.4 - 12
9y = 32.4
y = 3.6
So the paperback's mass is 0.6 pounds and textbook is 3.6 pounds
There is one solution that the intersecting lines have cause two solution doesn't have the same slope.
Divide 71 and 5 to get a decimal since 71 does not end with 5 or 0. Do it to get 14 1/5 or 14.2
