Hello there! We are talking about 86 being part of a number, so we are looking for the whole. To find the number we are looking for, we can write and solve a proportion. Set it up like this:
86/x = 45/100
86 is 45% of a number. We know the part, so now we are looking for the whole. 45% is part of 100%, so we put that part together. Cross multiply the digits. 100 * 86 is 8,600. 45 * x is 45x. That simplifies to 8,600 = 45x. Now, divide each side by 45 to isolate the x. 45x/45 cancels out. 8,600/45 is 191.1111111 or 191 1/9 in fraction form. There. x = 191 1/9 86 is 45% or 191 1/9
Note: Or, if you have to round to the nearest whole number, the answer is 191, or if you have to round to the nearest tenth, the answer is 191.1. It all depends on if the answer needs to be rounded or exact.
Okay. For these types of problems, you must do order of operations (PEMDAS). Parenthesis, Exponents, Multiplication, Division, Addition, Subtraction. Mind you that you do these steps from left to right, and multiplication and division is done from left to right. Same thing with addition and subtraction. With that being said, here are your answers if you do the expressions correctly.
1. 12
2. 106
3. 42
As the exercise says, the triangles are similar. So, we can set up proportions between correspondent sides.
In order to solve for x we can set up the proportion between the horizontal and vertical sides:

Solving this proportion for x implies 
Now you can solve for m and p using the pythagorean theorem, because both triangles are right:

Then, we know that the hypothenuse of the big triangle is m+p, so we have

which implies

The answer is D I just took the test
Answer:
13.0 inches
Step-by-step explanation: