Answer:
b) trapezoids
Step-by-step explanation:
a trapezoid has atleast one pair of opposite parallel sides
The formula for the circumference is C=2piR (r is radius)
If the flagpole is in the center and it's 15 feet to the edge, that means that 15 feet is the radius. Draw it out, you'll see. Now you plug 15 into the formula, either use a calculator or don't, and solve. You will get
94.2 as your circumference.
Answer:
The answer is 10.5 in decimal form
Answer:
First brand = 18 gallons
Second brand = 12 gallons
Step-by-step explanation:
Let the first brand brand be A and the second brand be B.
Thus, since he wants to obtain 30 gallons of a mixture that contains 30% pure antifreeze, then we have;
A + B = 30 - - - (eq 1)
Also; The first brand is 20% pure antifreeze, and the second brand is 45% pure antifreeze. Thus;
0.2A + 0.45B = (0.3 × 30)
0.2A + 0.45B = 9 - - - (eq 2)
From eq 1, we have; A = 30 - B
Put 30 - B for A in eq 2;
0.2(30 - B) + 0.45B = 9
6 - 0.2B + 0.45B = 9
0.25B = 9 - 6
0.25B = 3
B = 3/0.25
B = 12
Thus, A = 30 - 12 = 18 gallons
Since this is multiple choice ...
• check if B is correct:
x = 0, y = 4, z = 1 ⇒ 3x - y + 4z = -4 + 4 = 0 ≠ -10
(it's not)
• check if C is correct:
x = -2, y = 4, z = 0
⇒ 3x - y + 4z = -6 - 4 + 0 = -10
⇒ 3x - y + 4z = 2 + 4 + 0 = 6
⇒ 3x - y + 4z = -4 - 4 + 0 = -8
While this solution does satisfy the system, it can still have infinitely many other solutions that would work.
• check if D is correct:
Eliminate one of the variables from each equation. For instance,
(3x - y + 4z) + (-x + y + 2z) = -10 + 6
2x + 6z = -4
x + 3z = -2
and
(2x - y + z) + (-x + y + 2z) = -8 + 6
x + 3z = -2
but now it's impossible to eliminate one of the variables.
Therefore there are infinitely many solutions to the system [D].
