Sorry but i only know the answer to number 3
<span>
A rational number is a number that can be written as a fraction where numerator and denominator are both integers (and the denominator is not zero).
Since 0.57 = 57/100, so the number 0.57 can be written as a fraction where the numerator (57) and denominator (100) are both integers. </span>
11.0
12.40
13.5
14.80
15.8
16.17
2x-3y=1
+2x+3y=2
4x=3 substitute 3/4 for x in the first equation..you get y=2/9.
x=3/4
Y=x+12
(-4,8)
(10,22)
y=4x
(5,20)
(-4,-16)
(0,0)