Answer:
C. 18 cm
Step-by-step explanation:
The ratio of the sides of the triangle shown is 12 : 15 = 4 : 5. We know it is a right triangle, so we know the missing side length completes the ratio
3 : 4 : 5 = 9 : 12 : 15
Half of XY is 9 cm, so the length of the entire chord is 18 cm.
_____
The chord is tangent to the inner circle, so makes a 90° angle with the radius to that tangent point. This tells you that the triangle shown is a right triangle. It also tells you that the short radius bisects the chord. The Pythagorean theorem can be used to find the length of the side not shown (half the chord length).
The unknown side (a) can be found from ...
15² = 12² +a²
225 -144 = a² . . . . . . subtract 12²
81 = a² . . . . . . . . . . . simplify
9 = a . . . . . . . . . . . . . take the square root
The chord length is 2a, so is ...
2(9 cm) = 18 cm . . . . length of chord XY
Answer:
The expressions are not equivalent because -3(2)(5-4)+3(2-6)=-18 and -12(2)-6=-30
Step-by-step explanation:
Two expressions are said to be equal if after a number is substituted to the expression, they produce the same result (that is they have the same value).
To determine whether -3x(5-4)+3(x-6) is equivalent to -12x-6, we have to substitute the same number to the expression and see if it produces the same result.
Substituting 2 to the first expression gives:
-3×2(5-4) + 3(2 - 6) = -6 - 12 = -18
Substituting 2 to the second expression gives:
-12(2) - 6 = -24 - 6 = -30
Since -3×2(5-4) + 3(2 - 6) = -6 - 12 = -18 and -12(2) - 6 = -24 - 6 = -30, the expressions are not equivalent because they do not produce the same result.
Answer:
the distance is -2
Step-by-step explanation:
because you subtract
Notice that if you go forward, the common ratio is 5. Each new term is found by mult. the previous term by 5.
If, on the other hand, you go backwards (terms decreasing), then you divide a term to find what the previous term was.
Here, divide 1 by 5 to find the first term. It's 1/5.
(1/4)^-2 - (5^0 x 2) x 1^-1 =
(4/1)^2 - (1 x 2) x 1 = 16-2 = 14
If you raise something to the power of -2, swap numerator and denominator and remove the minus.
So (1/4)^-2 = 4^2 = 16
Also 1^-1 is just 1, not -1.
