5x²+13x-4-17x²-7x+19+15x²+5x-21x-7=
=5x²+15x²-17x² +(13x-7x+5x-21x) -4-7+19=
=3x²-10x+8
C because it's x means weeks so $5 a week is 5x and she already has 127 so 5x+127.
Given:
Diameter of the hole = 30 cm
To find:
The area of the hole.
Solution:
The radius of a circle is always half of the diameter. It is given that the diameter of the hole is 30 cm. So, the radius of the hole is:


Area of a circle is:

Putting
and
in the above formula, we get



Therefore, the area of the hold is 706.5 square cm.
2x is not a way to express this. You could use 2 + x or x +2. But 2x is x multiplied by 2. x + 2 is x plus 2.
Amount of dresses you could make with material and how many marbles can fit into a container.