6x8 = 48
48x10 = 480
480>460, which means that her estimate is not reasonable already, as the number will be much greater than the actual answer.
It is jsut meaning double the first number and is the 16 suppose to be added on?
7x7=49+16=45
The range is from 19 up to infinity. As x gets really negative, like -10,000 and -100,000, 2^x becomes closer and closer to 0; when it becomes essentially negative infinity, the value of 2^x becomes 0. As x gets really positive, the value of 2^x becomes extremely large.
The range of this function is from 19 to infinity.
comparing the relation given
thus y= -2x +1 to the general equation of a line
where y= mx + c
where m is the gradient and c is the intercept on the y-axis.
from the question, the gradient is -2 and since the line is perpendicular, the gradient is given as

so substituting the value of m in to the equation

=

as the gradient
equation of line is given by
y - y1 = m( x-x1)
from the question y1= -2 and x1=1
substitute them
y-(-2) = 1/2 (x -1)
y+2 =1/2 (x-1)
multiplying through by 2
2 (y+2) = x-1
2y +4 = x-1
2y =x-1-4
2y =x-5
x -2y -5 = 0
therefore the equation for the line is x-2y -5=0