Step-by-step explanation:
Substitute the y in the 1st equation with the 2nd equation.
7x + 10(2x + 9) = 36
7x + 20x + 90 = 36
27x + 90 = 36
3x + 10 = 4
3x = -6
x = -2
So now we can find y.
y = 2x + 9 = 2(-2) + 9 = (-4) + 9 = 5.
So x = -2, y = 5.
Answer:
22.5
Step-by-step explanation:
Hi there! Use the following identities below to help with your problem.

What we know is our tangent value. We are going to use the tan²θ+1 = sec²θ to find the value of cosθ. Substitute tanθ = 4 in the second identity.

As we know, sec²θ = 1/cos²θ.

And thus,

Since the given domain is 180° < θ < 360°. Thus, the cosθ < 0.

Then use the Identity of sinθ = tanθcosθ to find the sinθ.

Answer
- sinθ = -4sqrt(17)/17 or A choice.
I'm not going to do the entire question, but I'll do the first part.
For the first part, you have to set up an inequality. Use context clues, such as
no more than (the one used in this sentence) to figure out what the symbol should be for the inequality.
In this case, because it is NO MORE THAN 6400, it would be:
6400

250r + 475p
where r represents the # refrigerators, and p represents the # pianos
Now that you have the equation, make the graph, then for the 3rd part, plug in 12 and 8 to r and p to see if it keeps the inequality true.
Hope this helps! :)
Answer:
A. 45°
Step-by-step explanation:
When we are given two measurements of interior angles we add both of those angles together.
Also know that a triangle equals 180 degrees
So when we write out this expression 

Hope this helps