The correct answer to your question is going to be option C. if we look at the equation 4x + 7 = 31, we can see that 4x stands for a number that changed depending on how much of something x can be. the 7 in the equation stands for something doesnt change depending upon variables how much or how little x will be. knowing this, if we look at option C we read that each phone case cost $7 while $4 is how much it costs to ship. since this problem is about how many $4 phone cases Taliba can get, C would incorrect because they say that $7 is the post of each phone case. let me know if you have any further questions :)
<span>C. Taliba has $31 to order phone cases online. Each phone case costs $7, and there is a $4 shipping charge. How many phone cases, x, can Taliba buy?
The half-life of Radium-226 is 1620 years. If we divide 3240 by 1620 the answer is 2. So that means the amount of Radium-226 will divide in half twice.