What is the solution to the expression -2 - 3 - (-4)?

○-9
○-3
○-1
○5​

Aquantity with an initial value of 3900 decays exponentially at a rate of 35% every hour. what is the value of the quantity after 0.5 days, to the nearest hundredth?

One number is 4 less than 3 times a second number. if 3 more than two times the first number is decreased by 2 times the second number, the result is 11. use the substitution method. what is the first number?

If np3 /nc2 = 6, find the value of n