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
Answer:
Step-by-step explanation:
both the length and the width of a square is the same measurement.
so if both measured to "x" then that means one side increase +7.
so one side is x + 7
and the other side decreased -4
so the other side is x - 4
area of square = length x width or just one of the sides to the power of 2
so (x+7) * (x-4) = Area
x^2 + 3x - 21 = area
