True-false: the number 0.4 can be written as 4/10, so it is rational number

True

all rational numbers can be written in the form a/b where a and b are integers and b≠0

4 and 10 are integers and 10≠0 so it is a rational number

Well, the answer to this question would be 

50 % is the answer !

X= 49; x = 4step 1: foilstep 2: equal both to 0step 3: find x individually