Be sure to answer all parts. the area of a telescope lens is 6.490 × 103 mm2. (a) what is the area in square feet (ft2)? enter your answer in scientific notation.

To answer this question, you need to understand how to convert a unit. In this case, the conversion would be milli meter to feet. Since it area(the unit is ^2), the conversion needs to be done twice.
The calculation would be:
(6.490^10^3 mm2) / (304.8mm/ft) / (304.8mm/ft) = 0.06985= 6.985* 10^-2 ft2

x=3, y=8; (3,8)

Step-by-step explanation:

To use the substitution method, first solve for a variable.

2x+y=14

2x+y(-2x)=14(-2x)

y=14-2x

Now substitute y in the other equation with 14-2x

5x-2(14-2x)= - 1

Simplify by multiplying inside the parenthesis.

5x-28+4x= - 1

Combine the x values

9x-28= - 1

9x=27

x=3

Now substitute the x value in to solve for y

2(3)+y=14

6+y=14

y=8