X+y+z=51
y=2z
z=9+x
subsitute those
x+2z+9+x=51
x+2(9+x)+9+x=51
x+18+2x+9+x=51
4x+27=51
minus 27 both sides
4x=24
divide by 4
x=6
sub back
z=9+x
z=9+6
z=15
y=2z
y=2(15)
y=30
the numbers are
6,30,15
15. 
Step 1: Distribute the subtraction sign to all the numbers in the second set of parentheses...


Step 2: Combine like terms (
's go with
's)




Step 3: Combine like terms (
's go with
's)




Step 4: Combine like terms (normal numbers go with normal numbers)

1 + 2
3

You were correct!
16. 
I don't really know how to explain this one but I got: (7m-6n)(7m-6n)
The secant of a circle is any line that intersects two points on the circumference of the circle.
In the given circle, the lines EF and XY intersects two points on the circumference of the circle and hence are secants of the circle.
From the answer options given, the secant line is line XY.
Answer:
4x³ + 4x² + 5
Step-by-step explanation:
3x³ - 2x + 8 + 2x² + 5x + x³ + 2x² - 3x - 3.
4x³ - 2x + 8 + 2x² + 5x + 2x² - 3x - 3
4x³ + 4x² - 2x + 8 + 5x - 3x - 3
4x³ + 4x² + 8 - 3
4x³ + 4x² + 5
The answer is A, as for every 48 stickers there are two sheets :)