Answer:
11) A
12) B
Step-by-step explanation:
11) 10x² + 1 = 0
Subtract 1 from both sides:
10x² = -1
Divide both sides by 10:
x² = -1/10
Take the square root of both sides:
x = ±√(-1) / √(10)
Remember that the square root of -1 is i:
x = ±i / √(10)
To rationalize the denominator, multiply top and bottom by √10.
x = ±i√(10) / 10
Answer is A.
12) 2v² + 8v + 6 = 0
Divide both sides by 2:
v² + 4v + 3 = 0
Use AC method or quadratic formula to factor:
(v + 1) (v + 3) = 0
Set each expression to 0:
v + 1 = 0 or v + 3 = 0
Solve:
v = -1 or v = -3
Answer is B.
This is what it would look like if graphed
Average speed=totaldistance/ttoaltime
d=rt
40mph for 30mins (1/2 hr), travels 20mi
rest for 15min (1/4 hr), travels 0mi
swims at 32mph for 45min (3/4hr), travels 96/4=24mi
total distance=20+0+24=44
total time=1/2+1/4+3/4=1 and 1/2=3/2
44/(3/2)=44 times 2/3=88/3=29 and 1/3
about 29 and 1/3 mph
Formula = 4/3 x pi x r^3
4/3 x 3.14 x 7^3 = 1436.03
answer: a. 1436.03 cubic units
Answer: the cost of a cheeseburger is $4
Step-by-step explanation:
Let x represent the cost of one cheeseburgers.
Let y represent the cost of one Soda.
The patriot diner sells 2 cheeseburgers and one soda for $11.00. It means that
2x + y = 11 - - - - - - - - - - - 1
She also sells 3 cheeseburgers and 2 sodas for $18.00. It means that
3x + 2y = 18 - - - - - - - - - - -2
Multiplying equation 1 by 3 and equation 2 by 2, it becomes
6x + 3y = 33
6x + 4y = 36
Subtracting, it becomes.
- y = - 3
y = 3
Substituting y = 3 into equation 1, it becomes
2x + 3 = 11
2x = 11 - 3 = 8
x = 8/2 = 4
