Answer:
see explanation
Step-by-step explanation:
Given the 3 equations
3x + 5y + 5z = 1 → (1)
x - 2y = 5 → (2)
2x + 4y = 11 → (3)
Use (2) and (3) to solve for x and y
Multiply (2) by 2
2x - 4y = 10 → (4)
Add (3) and (4) term by term
4x = 21 ( divide both sides by 4 )
x = 
Substitute this value of x into (3)
2 ×
+ 4y = 11
+ 4y = 11 ( subtract
from both sides )
4y =
( divide both sides by 4 )
y = 
Substitute the values of x and y into (1) and solve for z
3 ×
+ 5 ×
+ 5z = 1
+
+ 5z = 1
+ 5z = 1 ( subtract
from both sides )
5z = -
( divide both sides by 5 )
z = - 
Solution is
x =
, y =
, z = - 
Total marbles = 7 + 12 + 8 + 5 = 32
Green marbles = 8
Yellow marbles = 12
P(green ,then yellow) = (8/32)(12/32) = 3/32
Answer: The probability is 3/32
Answer: 2.5 minutes
Explanation: Divide the time by the amount of pages to find the amount of time spent of each page. (30/12=2.5)
Given u/7 - 1 = 7 and plugging in values for u,
For u = 28; 28/7 - 1 = 4 - 1 = 3; No
For u = -49; -49/7 - 1 = -7 - 1 = -8; No
For u = 42; 42/7 - 1 = 6 - 1 = 5; No
For u = 0; 0/7 - 1 = -1; No
Another way to find out which value would be a solution to u/7 - 1 = 7 is to solve for u.
u/7 - 1 = 7
u/7 = 7 + 1
u/7 = 8
u = 8*7
u = 56
The only solution to this equation is when u = 56.
From the circle geometry theorem, a tangent to a circle makes 90° angles with the radius of the circle.
RQ is perpendicular to QP
Triangle RQP is a right-angled triangle
by Pythagoras theorem

units (rounded to one decimal place)