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
The answer I believe is -36
84 and 6 i believe not sure tho
complementary adds to 90°
The rate of interest is 25%
<u>Explanation:</u>
Given:
Principal, P = $2,000
Amount, A = $2500
Time, t = 1 year
Rate of Interest, r = ?
We know:

On substituting the value we get:


Therefore, the rate of interest is 25%