That technique for solving equations is: Whatever you do to one side of the equation, you have to do to the other side to preserve the equality The technique for solving inequalities is: Whatever you do to one side of the inequality, you have to do to the other side to preserve the inequality. the techniques are the same. The difference between solving equations and solving inequalities is: If you multiply or divide an inequality by a negative number, then the inequality reverses. !!!!!
Answer:
- Benito's error was using the equal sign (=) instead of the congruency symbol (≅).
Explanation:
Benito's error was using the equal sign (=) instead of the congruency symbol (≅).
The congruency symbol (≅) means that the elements (segments, angles or figures in general) have the same measure, i.e. they have equal lengths for the segments or equal measure for the angles.
For instance, it is an error saying that the segment AB is equal to the segment BC because, as you clearly see in the picture, they are not same; they have the same length but they are joining different points, that makes them different in essence, although they have the same length. They would be equal only if they are the same figure.
In mathematics, you must not say that two different segments or two different angles are equal but they are congruent, which means that their lengths are equal. The use of equal is reserved for numbers and variables, not for figures like segment, points, angles, polygons.
Answer:
k=20
Step-by-step explanation:
when x approaches 4, the denominator x-4 approaches 0
if the denominator is 0, it means that this is invalid
if the function is a number over 0 when x=4, it represents a vertical asymptote, which means no limit
so the only way possible to let there be a limit is to let the function be 0/0 when we plug in x=4
so x^2 + x - k = 0 when x = 4
4^2 + 4 - k = 0 ==> 20 - k = 0 ==> k = 20
Answer:
C. 434π
Step-by-step explanation:
Given:
Radius (r) = 7 in.
Height (h) = 24 in.
Required:
Surface area of the cylinder
Solution:
S.A = 2πrh + 2πr²
Plug in the values
S.A = 2*π*7*24 + 2*π*7²
S.A = 336π + 98π
S.A = 434π
Answer:
Let the speed of the train be x km/h.
Case 1:
Distance = 288 km
Speed = x km/h
Time = Distance/Speed
= 288/x h
Case 2:
Distance = 288 km
Speed = (x+4) km/h
Time = 288/x + 4 h
Since 288/x > 288/x + 4
288/x - 288/x+4 = 1
288[1/x - 1/x+4 ] = 1
[ x + 4 - x / x(x + 4) ] = 1/288
[4 / x^2 + 4x ] = 1/288
x^2 + 4x = 1152
x^2 + 4x - 1152 = 0
x^2 + 36x - 32x - 1152 = 0
x(x + 36) - 32(x + 36) = 0
(x + 36)(x - 32) = 0
x + 36 = 0 , x - 32 = 0
x = -36 , x = 32
x = -36 , rejected since speed cannot be negative.
Therefore , speed of the train = 32 km/h
