Answer:
Explanation:
For its solution just translate in portugese (because I do not know portugese, sorry)
Proportinality means that if we increase one value, the other will be alse increased in the same way. So this is expressed in the formula y=k*x , where k is a constant that will help us to value the value of b.
We know already that x=15 and y=1,2 so we replace them to the formula:
y=k*x => 1.2=k*15 => k=0.08
With k=0.08, now we will find the value of b
y=k*x => b=0.08*6 => 0.48
The formula that we used was : y=0.08*x