Area of a circle is pi x r ^2
R = diameter/2
R = 1.8/2 = 0.9
Area = 3.142 x 0.9^2
Area = 2.5 square cm.
Answer:
They should insert that y value into the other equation.
Step-by-step explanation:
Just guess and check. For example, for the first on the left, I guessed 3 to begin with. 3 + 3 + 3 = 9, but 10 + 3 = 13, so 3 is not the answer. I then guessed 5. 5 + 5 + 5= 15, and 10 + 5= 15, so star = 5.