2+y=9 3x-7y=3 solve the system by the substitution

80/3 or 26 2/3

Step-by-step explanation:

-2 + y = 9 (subtract y from both sides)

-2 = 9 - y (subtract 9 from both sides)

-2 - 9 = y (multiply both sides by -1)

2 + 9 = y (simplify)

11 = y (substitute)

3x - 7 (11) = 3 (multiply)

3x - 77 = 3 (subtract 3 from both sides)

3x - 80 = 0 (subtract 3x from both sides)

-80 = -3x (multiply both sides by -1)

80 = 3x (divide both sides by 3)

80/3 = x (simplify if needed)

26 2/3 = x

D.   ft²

Step-by-step explanation:

Scientific notation of a number is expressed in the following form,

Where,

a = decimal number (1 ≤ |a| < 10)

b = the power of 10 whereby the scientific notation is equivalent to the original number.

To express 4,356,000 square feet in scientific notation, do the following:

1. Move the decimal point to the left up to the last non-zero digit =  a = 4.356

2. Since we moved the decimal point by 6 decimal places, therefore, b = 6

3. Substitute the values of the variables into  

Thus:

4,356,000 = 3. Substitute the values of the variables into  

a * 10^b

Thus:

4,356,000 = 4.356 * 10^6