Which of the following situations combine to make zero? A- A friend opens a checking account with $30. His first purchase made with his debit card totals $28

B- The temperature falls 10 degrees below zero and then rises 20 degrees to be 10º F

C- A friend borrows $20 and promises to return double the amount.

D- A start up business has income equal to its expenses.

D

Step-by-step explanation:

Why A is wrong:

If a friend has $30 in his checking account and he made a purchase of $28, the equation would be:

30-28 = $2, which does not equal zero.

Why B is wrong:

The temperature was zero and went down to negative ten. It went up to 10, not zero. So this is also wrong.

Why C is wrong:

A friend borrowed $20 dollars and promised to return double the amount, $40. The equation for this is:

20 - 40 = -20, which also does not equal zero

Why D is correct:

Income is how much you earn

Expenses is how much you pay.

If both of them are equal, then your income is zero, which is the correct answer.

Hope this helps :)

-jp524

explanation:

infrared radiation has wavelength in the range between 700 nm and 1 mm. lets' convert these values into scientific notation, keeping in mind that:

let's start from the lower value, we have:

(we moved the dot two places to the left, so we increased the exponent by 2 units, from -9 to -7)

the higher value is:

so, the range of wavelength of infrared radiation is:

2x + 8

step-by-step explanation: