Answer:
Step-by-step explanation:
Let x be the number of 2 coins and y be the number of 5 coins. Let z be the number of 10 coins she exchanged. Then, we have the first equation

Since she has one 5 coin less than 2 coins, then y=x-1. So we get the equation
which is equivalent to
If we add 5 on both sides and factor out on the right by 5 we get

We can solve for x and get
Since x represents the number of 2 coins, we must have that x is an integer. That is, we cannot have, for example 1.5 2 coins. Since 7 doesn't divide 5, we must have that 7 divides 2z+1. That is, the value of z is such that the number 2z+1 is multiple of 7. That is 2z+1 = 7p where p is an integer.
If that is the case, then
x = 5p, then y = 5p-1. By having 2z+1 = 7p, we are forcing that p is an odd integer, so we have infinite solutions. For each value of p that is an odd integer, then x=5p and y=5p-1 is a solution to the problem
2,862 bacteria
6,200/26 = x/12
For one hour, there are 238.461538. Multiply that by 12 and get 2861.53846. Round to the nearest whole number and your answer is 2,862 bacteria.
Answer:
a). -65
b). -61
c). -20ab + 3bc +3ac
Step-by-step explanation:
According To the Question,
a). the sum of 72 − 104 + 5 and -32 + 4 - 10 .
- (72 − 104 + 5) + (-32 + 4 - 10)
- (-27) + (-38)
- -27 - 38
- -65
b). What should be added to 32 + 32 + 3 to get 3 + 3 , Let X be Added .
- Thus, (32 + 32 + 3) + X = 3 + 3
- 67 + X = 6
- X = 6 - 67
- X = -61
c). Subtract the sum of 12ab –10bc –18ac and 9ab + 12bc + 14ac from the sum of ab + 2bc and 3bc – ac.
- Thus, [(ab + 2bc) + (3bc – ac)] - [( 12ab –10bc –18ac) + (9ab + 12bc + 14ac)]
- (ab + 5bc - ac) - (21ab + 2bc - 4ac)
- ab + 5bc - ac - 21ab - 2bc + 4ac
- -20ab + 3bc + 3ac
Answer:
4 hours
Step-by-step explanation:
$50 - $14 = $36
36 / 9 = 4