put in an positive number for x and check
2 - 5 = -3
5 - 2 = 3
- 2 + 5 = 3
5 + (-2) = 2
so the only different one is the first
<span>60.5 milligrams per square centimeter
First, determine how many half lives have expired by dividing the time by the half-life. So:
55/20 = 2.75
That means that only 2^(-2.75) = 0.148650889 = 14.8650889% of the original substance remains. So just divide the amount remaining by 0.148650889 to get the original amount.
9 / 0.148650889 = 60.5445419
So originally, there was 60.5 milligrams per square centimeter 55 years ago.</span>
(a) Answer: One solution.
Explanation: two lines that have same slope with opposite sign will necessarily cross each other at a single point, as one is "pointing uphill" and the other "downhill."
(b) Answer: Infinitely many solutions.
Explanation:
2x + 3y = 5.5
4x + 6y = 11 | divide by 2
-->
2x + 3y = 5.5
2x + 3y = 5.5
--> equations are identical.
2x + 3y = 2x + 3y
so any (x,y) will satisfy this equation. This means infinitely many solutions.
(c) Answer: One solution
Explanation:
Continuing the two lines it becomes obvious they will cross at one point (the solution)
(d) Answer: No solution
Explanation: If the two lines are parallel, they will never cross (by definition of "parallel"). Therefore there will be no solution to the corresponding linear system.
Answer: ??? What
Explanation: what’s the question??