X - the number of pencils
y - the number of pens
She has twice as many pencils as she has pens.
Tom borrows a pen, so she has y-1 pens. Now she has ten less pens than pencils.
Set 2y and y+9 equal to each other:
She has 9 pens.
Answer: Proportional reasoning compares ratios to answer questions.
A trinomial is a polynomial with three terms. It can be determined if it is a difference of two squares when you factor it.
The resulting factor of a trinomial that is a difference of two squares is: a²<span> – b</span>²<span> = (a + b)(a – b) or (a – b)(a + b)</span>
You will notice that the middle term is missing. This means that the middle term zeroes out as a result of having the same number of different signs (+ and -)
Company a = 22 + 0.07m
company b = 8 + 0.12m
We are looking for the time when the prices are equal. i.e. the price of company a = the price of company b
company a = company b
22 + 0.07m = 8 + 0.12m
22 - 8 = 0.12m - 0.07m
14 = 0.05m
m = 14/0.05
m = 280
Therefore, the two companies will cost the same if you talk for 280 minutes
Substitute.
2x+(2x -15) = -3
4x -15 = -3
Add 15 to both sides
4x = 12
Divide by 4
X=3
2(3) + y = -3
6+y=-3
-6 from both sides
Y=-9
(3,-9)
