Answer:
B. 10
Step-by-step explanation:
First, we need to recognize that the two triangles are similar (the triangle with a leg value of 21 and the triangle with a leg value of 4 and hypotenuse x)
Let's first label the leg of the second triangle as y.
Then, we can set up this equation

Cross multiplying gives us
84=y^2
So, y=sqrt(84) or 2 sqrt(21).
Now, using the pythagorean theorem, we get
4^2+2sqrt(21)^2=x^2
100=x^2
x=10
Answer:
25% increase
Step-by-step explanation:
Take the new number and subtract the original amount
90-72 = 18
Divide this amount by the original amount
18/72 = .25
Multiply by 100
25%
This is the percent increase
Does that mean solve for y? If so, here it is:
5x + 2y = 11.
Move the x term by subtracting.
2y = -5x + 11
Divide by 2.
y = -5/2x + 11/2
Your equation should look like this:
d = day
15 + 3.50d
Hope this helps!