I'm not 100% sure because it is rare to ask about adding scientific notation but I would answer it like this:
8.4x10^8 +3.7x10^9=
12.1 x 10^17
final answer
Let the first integer be x. Then the next consecutive integer is x+1.
Translating the word problem into symbols, x(x+1)-20(x+1) = 442.
Then x^2 + x - 20x - 20 = 442
or x^2 - 19x - 462 = 0
Solve by completing the square:
x^2 - 19x + 90.25 - 90.25 - 462 = 0
(x-9.5)^2 - 552.25 = 0
Taking the positive square root of both sides, we get x-9.5 = 23.5, or
x = 33
The two consecutive integers are 33 and 34.
Check: (33)(34)-20(34) = 442 (as expected).
Answer: There is a difference between rote counting and rational counting. Rote counting involves the memorization of numbers. Rational counting tells children "how many there are." For children to count rationally, they need to demonstrate one-to-one correspondence.
Answer:
Yes
Step-by-step explanation:
Her answer makes sense because 1800 ÷ 9 is 20
Answer:
Option D is correct
The initial value is 2
Step-by-step explanation:
The equation of line passes through the origin is represented by:
y = mx where m is the slope or unit rate .
Direct Proportionality says that:
if
then the equation of the form is y = kx where k is the constant of proportionality.
Given the equation: 
Then by definition:
m = 2
⇒ Slope on the line is 2.
⇒ the unit rate is 2.
Also, the constant of proportionality is 2.
Therefore, the statement which is not true for the equation y=2x represents a set of data is: The initial value is 2