Answer:
A
Step-by-step explanation:
The total class is 10
the number of girls is 7
ratio of girls to total students - 7:10
Answer:
B (5, 13)
Step-by-step explanation:
9x + 4y = 97
9x + 6y = 123
To solve by elimination, we want to <em>eliminate</em> a variable. To do this, we must make one variable cancel out.
First, we can see that both equations have 9x. To cancel out x, we must make <em>one</em> of the 9x's <em>negative</em>. To do this, multiply <em>each term</em> in the equation by -1.
-1(9x + 6y = 123)
-9x - 6y = -123
This is one of your equations. Set it up with your other given equation.
9x + 4y = 97
-9x - 6y = -123
Imagine this is one equation. Since every term is negative, you will be subtracting each term.
9x + 4y = 97
-9x - 6y = -123
___________
0x -2y = -26
-2y = -26
To isolate y further, divide both sides by -2.
y = 13
Now, to find x, plug y back into one of the original equations.
9x + 4(13) = 97
Multiply.
9x + 52 = 97
Subtract.
9x = 45
Divide.
x = 5
Check your answer by plugging both variables into the equation you have not used yet.
-9(5) - 6(13) = -123
-45 - 78 = -123
-123 = -123
Your answer is correct!
(5, 13)
Hope this helps!
9514 1404 393
Answer:
x = 25
Step-by-step explanation:
The parallel lines divide the triangle sides proportionally.
x/40 = 15/24
x = 40(15/24) . . . . multiply by 40
x = 25
Answer:
a) 0.2347, 0.0007
b) 1.30
c) 0.63
Step-by-step explanation:
Given –
Mean = 73.4
Sigma = 4.7
Probability that the speed is greater than 70 is
P (X>70) = P (z> (70-73.4)/4.7) = P (z>-0.72) = 0.7653
a) The probability that a car is not speeding = 1 - 0.7653 = 0.2347
The probability that all 5 cars are not speeding = (0.2347)5 = 0.0007
b) E (X) = 1/p = 1/0.7653 = 1.30
c) Standard deviation = Sqrt (1-p/p) = (1-0.7653)/0.7653 = 0.63
