The function is
y=0,7x+80
and they ask you the point (6, )
this means x=6
so we need to replace x=6 on the function and find out the value of y
Y=0,7*6+80
Y=4.2+80=84.2
So the answer is: (6, 84.2)
and this means that 6 years before 1999, the number of households that have at least one microwave is 84.2 million
For C. 2014 is (2014-1999=15) 15 years after 1999
So we replace x=15
Y=15*0,7+80=90.5
So the answer is: 90.5 million households