I think this is more of an opinion question. What someone could solve mentally may not be the same as someone else's.If it were my worksheet, I'd circle all of them but it may be different for you.
At your level, I'd probably circle:
54 - 10
93 - 20
and 39 - 2
Answer:
(x, y) = (2 2/9, -1 4/9)
Step-by-step explanation:
Equate the values of y and solve for x.
1/4x -2 = -2x +3
(2 1/4)x = 5 . . . . . . . . add 2+2x to both sides
x = 20/9 = 2 2/9 . . . multiply by 4/9
y = -2(2 2/9) +3 = -4 4/9 +3 . . . . substitute for x in the second equation
y = -1 4/9
The solution is x = 2 2/9, y = -1 4/9.
? can be any number except for 3 or -2 as it is already used in (3,4), (-2,-5)
(12 - 2) * 180 = 1,800/12 = 150
(8 - 2) * 180 = 1,080/8 = 135
B. 8 sides
Answer: The perimeter of the rectangle is 28 centimeters.
Step-by-step explanation: I hope this helps-