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 domain is the set of allowed x inputs, or x coordinates of a function. In this case, any point on the curve has an x coordinate that is 4 or smaller.
Therefore, the domain is the set of numbers x such that 
To write this in interval notation, we would write ![(-\infty, 4]](https://tex.z-dn.net/?f=%28-%5Cinfty%2C%204%5D)
This interval starts at negative infinity and stops at 4. We exclude infinity with the curved parenthesis and include 4 with the square bracket.
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The range is the set of possible y outputs. Every point on this curve has a y coordinate that is either 0 or it is larger than 0.
The range is the set of y values such that 
In interval notation, it would be written as 
This time we start at 0 (including this endpoint) and "stop" at infinity
note: we always use curved parenthesis at positive or negative infinity because we cannot reach either infinity
x - y = 16
x^2 + x^2 = 130
----------------
x^2 - y^2 = 256
+(x^2 + y^2 = 130)
2x^2 = 386
x^2 = 193
x = <span>13.892 (3DP)
----
</span>x - y = 16
13.892 - y = 16
-y = 2.108
y = -2.108
The numbers are: 13.892 and -2.108
Answer:
10^-1*2.65
Step-by-step explanation:
two hundred sixty-five thousandths= 0.265
We need a number between 1 and 10, to do the multiplication in standard form, so 0.265 turns into 2.65.
Because 2.65 becomes, smaller we use a negative power. We only move the decimal place once to the left, so we would multiply 2.65 by 10^1.
10^-1*2.65=0.265
