Answer:
he added wrong
Step-by-step explanation:
(x,y)=(x+4,y+7)
(4,5)
(4+4, 5+7)
(8, 12)
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
1: 5 2: 9 or 10
For question 1 we can round 115 to 100, 5x100 is 500 which is closer to 545 than 7x100 = 700.
Answer:
x=-1.8, x=-8.2
Step-by-step explanation: