Answer:
Step-by-step explanation:
You know how subtraction is the <em>opposite of addition </em>and division is the <em>opposite of multiplication</em>? A logarithm is the <em>opposite of an exponent</em>. You know how you can rewrite the equation 3 + 2 = 5 as 5 - 3 = 2, or the equation 3 × 2 = 6 as 6 ÷ 3 = 2? This is really useful when one of those numbers on the left is unknown. 3 + _ = 8 can be rewritten as 8 - 3 = _, 4 × _ = 12 can be rewritten as 12 ÷ 4 = _. We get all our knowns on one side and our unknown by itself on the other, and the rest is computation.
We know that 
; as a logarithm, the <em>exponent</em> gets moved to its own side of the equation, and we write the equation like this: 
, which you read as "the logarithm base 3 of 9 is 2." You could also read it as "the power you need to raise 3 to to get 9 is 2."
One historical quirk: because we use the decimal system, it's assumed that an expression like 
uses <em>base 10</em>, and you'd interpret it as "What power do I raise 10 to to get 1000?"
The expression 
means "the power you need to raise 10 to to get 100 is x," or, rearranging: "10 to the x is equal to 100," which in symbols is .
(If we wanted to, we could also solve this: 
, so 
)
Answer:
y= -69/8 (negative 69 over 8)
Step-by-step explanation:
First, you have to simplify both sides of the equation:
Second, add 3/4 to both sides:
-2/3y +-3/4 + 3/4=5 +3/4
-2/3y= 23/4
Next, multiply both sides by 3/(-2) (3 over -2)
(3/-2)*(-2/3y)= (3/-2) * (23/4)
<em><u></u></em>
<em><u>y= -69/8</u></em>
Answer:
82
Step-by-step explanation:
triangle adds upto 180 degrees
180 - (53+45) = 98
Then two lines adapt to 180 degrees
therefore, 180 -98 = 82
Answer: 600 ft.
Step-by-step explanation:
The height is 12, and the base is 50. So V=ABh=50·12=600ft³, just plug in the numbers.
Answer:
x=3
y=-2
Step-by-step explanation:
2x - 5y = 16
3x + 2y = 5
Solve for x in the first equation.
2x - 5y = 16
2x = 16 + 5y
x = (16 + 5y)/2
x = 8 + 5/2y
Put x as 8 + 5/2y in the second equation and solve for y.
3(8+5/2y) + 2y = 5
24+15/2y + 2y = 5
24 + 19/2y = 5
19/2y = 5-24
19/2y = -19
y = -2
Put y as -2 in the first equation and solve for x.
2x - 5(-2) = 16
2x +10 = 16
2x = 16-10
2x = 6
x = 3
