Answer: 13,864,675 seconds
Step-by-step explanation:
I minute 15 seconds = 75 seconds
That means it takes 75 seconds to achieve 150 , and it takes x seconds to achieve 27,729,350. Interpreting this in proportion form , we have:
150 ------ 75 seconds
27,729,350 ------- x seconds
Then
150x = 27,729,350 X 75
150x = 2,079,701,250
x = 2,079,701,250 / 150
x = 13,864,675
That means it takes 13,864,675 seconds to achieve the goal , converting this to minutes, we have:
231,077.9 minutes
The trick here is to relate the NUMBER of coins to each other in one equation, and then the VALUE of the coins in another equation. If I have 1 dime, that 1 dime is worth 10 cents. The number of dimes is obviously not equal to the value. Let's call quarters q and dimes d. The number of these 2 types of coins added together is 80 coins. So q + d = 80. Now, we know that quarters are worth .25 and dimes are worth .1, so we express a quarter's worth as .25q; we express a dime's worth as .1d. The value of the coins we have is 14.90. So that equation is .25q + .1d = 14.90. Let's solve the first equation for q. q = 80 - d. We can now use that as a substitution for q into the second equation, giving us an equation with only 1 unknown, d. .25(80-d) + .1d = 14.90. Distributing through the parenthesis we have 20 - .25d + .1d = 14.90. Combining like terms gives us - .15d = - 5.1. We will divide both sides by - .15 to get that the number of dimes is 34. If we had a total of 80 coins, then the number of quarters is 80 - 34, which is 46. 46 quarters and 34 dimes
Answer: (-2,2)
Step-by-step explanation:
3x-4y=-14
2(3x+2y=-2)
3x-4y=-14
6x+4y=-4
9x=-18
x=-2
3(-2)-4y=-14
-6-4y=-14
-4y=-8
y=2
Answer:
Observational study
Step-by-step explanation:
- See the researcher visits the forest.
- She want to experience or observe the forest fire.
- She want to observe how it affects the animals.
- Hence it's observational study
