Answer:
$60
Step-by-step explanation:
If 50% of the original price is $30...
50% is half of 100% which is the whole.
50*2=100
30*2=60
The model is is I think 25 mentally
This is how I do it. If it is a negative minus a negative, I combine the two - signs to make it an addition problem. Ex. -3 - -4 makes -3+4. The answer would be one.
If it is a negative plus a negative, keep the sign on the greater number and take away the sign the smaller number. Ex. -7 + (-9). Keep the sign on the 9. -7 - 9. The answer would be -16.
To find x, first we'll split the triangle in two right triangles.
The first triangle will be the one with sides (8,x+4,y) and the second triangle will be the one with sides (12,2x+1,y).
As you can see, these two triangles share the side 'y'.
To solve we'll do the following; first solve for 'y' by applying the Pythagorean theorem in the second triangle, and finally solve for 'x' applying Pythagorean theorem in the first triangle.
From the second triangle (12,2x+1,y) we solve for 'y' by writing:

Now that we know 'y^2' we apply Pythagorean Theorem in the first triangle (8,x+4,y)


Now you solve the quadratic equation, you'll get a positive and negative value; as this are lengths, you take the positive and get: