Answer:
3x+4 Ralph is currently 12 years old.
Step-by-step explanation:
You can find the equation by reading the scenario given. When you read it, it says that Ralph is 3 times as old as Sara and since her current age is going to be used to represent x you will first get 3x. That automatically eliminates the second and third choice given. It then says the equation is for Ralph's age in four years which means to add four to the equation. This gives you 3x+4 as your equation.
When something is tripled and then in a few years it is doubled, it is easiest to first try the number that is being added. So in this case the number is four. When you multiply 4 by 3 you get 12. If Sara is 4 she'll turn eight in four years and if Ralph is 12 he'll turn 16 in four years. 16 divided by 2 is 8 which shows you that Ralph is currently 12
Answer:
x = 48°
Step-by-step explanation:
The sum of the 3 angles in a triangle = 180°, thus
x = 180° - (90 + 42)° = 180° - 132° = 48°
Answer:
$6.22
Step-by-step explanation:
Answer: $70 per year.
Step-by-step explanation:
Let's say that x is the number of years that has passed and y is how much the stamp is worth.
So we know that in zero years the stamp was worth $420 because that is the time Sheri gave her brother Sam the stamp. That could bring up the coordinates (0,420) .
Now we know that in 8 years it was worth $980 and that could be the coordinates (8,980)
To find the rate of change we need to find the different between the y value and divide it by the difference in the x values.
420 - 980 = -560
0-8 = -8
-560/-8 = 70
The rate of change is 70 which means that it grew by $70 every year.
