He pays $53.99 hope that help you
Let x be the number of months.
The first plan is 15 dollars sign up fee and 38 dollars per month. So the equation is 38x + 15.
The second plan is 78 dollars as sign up fee and 31 dollars per month. So the equation is 31x + 78.
We need find when x has the same value in both equations, so we do their equality:
38x + 15 = 31x + 78
Let's subtract 15 from both sides
38x + 15 = 31x + 78
38x + 15 - 15 = 31x + 78 - 15
38x = 31x + 63
Now let's subtract 31x from both sides to have the variables on a side and the numbers on side:
38x = 31x + 63
38x - 31x = 31x - 31x + 63
7x = 63
Divide both sides by 7 to have the variable x on a side and its value on the other:
(7x)/7 = 63/7
x = 9
So at month 9, the 2 plans will cost the same.
Let's check our answers, and let y be the cost:
y = 38x + 15 = 38*9 + 15 = 357
y = 31x + 78 = 31*9 + 78 = 357
Our answer has been approved.
Hope this helps! :D
I got:
−
8
f − 16
g
|-i dunno if it's right-|
I'd suggest you get rid of the fraction first. Mult. every term by 3. You will get
3y^2 + 10y + 3 = 0
From inspection, with coefficient a=3 and coeff. c = 3, the binomial factors could possibly begin with y or 3y: for example, y+1; also, the binom. factors may end in +1. Let's try the possible binomial factor 3y + 1.
Note that 10y separates into 9y+1y.
Then 3y^2 + 10y + 3 = 0 becomes
3y^2 + 9y + 1y + 3 = 0
Let's apply factoring by grouping:
3y^2 + 9y + 1y + 3 = 0
3y*(y + 3) + 1(y + 3) so y+3 is indeed a common factor.
Factoring y+3 out, we get (y+3)(3y + 1), which prove to be the correct set of factors. Multiply these together to ensure that the product is indeed y^2 + (10/3)y + 1.
