If the gum costs 75 cents today, which is 3 cents less than three times what the pack cost 20 years ago, we just need to arrange what we know into an equation.
We know that the price of gum today is 75 cents, so we can leave that on one side of the equation as a constant. Also, since we are dealing only with cents and not dollars, there is no need to shift the decimal point to the left.
? = 75
Now, we can work the equation.
The problem tells us that 75 is 3 cents less than three times the old cost. So, if x is the old cost, we can work out the equation based on that.
It says that it's 3 cents less than 3 times x. The question is basically the equation in word form.
3x - 3 = 75
'3x' being the "three times the old cost" part, '- 3' being the "3 cents less" part, and '75' of course being the current price of a pack of gum.
Option C is your correct answer.
BTW if we were to solve this, we would see that the old price of a pack of gum is:
3x - 3 = 75
+ 3 + 3
3x = 78
/3 /3
x = 26
20 years ago, a 75-cent pack of gum cost 26 cents.
Hope that helped! =)
Samuel exercises for 100 minutes each day. Or in other words, 1 hour and 40 minutes.
If the growth rate is a constant, we can model it using a linear equation:
y = b + ax
where b = initial value, a = growth rate.
In this case, x = m = number of months.
Let's find the equation for the growth of each species.
Species A:
Initial height = b = 25 cm
Growth rate = a = 3 cm per month
So its height can be modeled by H(m) = 25 + 3m
Species B:
Initial height = b = 10 cm
Growth rate = a = 8 cm per month
So its height can be modeled by H(m) = 10 + 8m
Thus the answer is A: H(m) = 25 + 3m and B: H(m) = 10 + 8m.
LCD is 12.
12 goes into 12 once. 12x1=12
12 goes into 60 five times. 12x5=60
