The 2 equations are
18.20x+19.50y=230.10
and
x+y=12
where x is the months of original cost and y is months for new cost. Since you know that you paid for one year (12 months) you can make the second equation. Then you want to substitute the first equations x by making the second equation
x=(12-y)
18.20(12-y)+19.50y=230.10
218.40-18.20y+19.50y=230.10
1.30y=11.70
y=9
so that means you had the original rate for 3 months and the new one for 9 months
Sqrt(1-3x)=x+3
[sqrt(1-3x)]^2=(x+3)^2
1-3x=(x+3)(x+3)
1-3x=x^2+6x+9
-3x=x^2+6x+8
0=x^2+9x+8
The answers are -1 and -8 BUT, we have to plug them back into the original equation to make sure we don't get a negative under the square root sign.
After doing this, we realize that only -1 works, so the answer is x=-1
Sorry that this took forever to answer. I was thinking of a good way to explain this, and if you need any further explanation, message me:)
Best wishes:)
Answer:
-45
Step-by-step explanation: no explanation
Answer:
see below
Step-by-step explanation:
sin x 1
------------------- = -----------
sec^2 x - tan ^2 x csc x
Sec = 1/cos and tan = sin/cos
sin x 1
------------------- = -----------
1/ cos ^2 x -sin^2/cos ^2 x csc x
Factor the denominator
sin x 1
------------------- = -----------
(1-sin^2 x)/ cos ^2 x csc x
We know that 1 - sin^2 x = cos ^2
sin x 1
------------------- = -----------
(cos^2 x)/ cos ^2 x csc x
sin x 1
------------------- = -----------
1 csc x
Multiply the top and bottom of the left hand side by 1/ sin x
sin x * 1/ sin x 1
------------------- = -----------
1 * 1 sin x csc x
1 1
------------------- = -----------
1 sin x csc x
We know that 1/sin x = csc
1 1
--------- = -----------
csc (x) csc x
