Let x = your number.
x^2 - 21 = 4x. Subtract 4x from both sides.
x^2 - 4x - 21 = 0. Factor.
(x - 7) (x + 3) = 0. Set each term to 0.
x + 3 = 0. Subtract 3 from both sides.
x = -3. This is the negative solution.
Set the other term equal to zero.
x - 7 = 0. Add 7 to each side.
x = 7. This is the positive solution.
Answer:
a. angles A and C
b. angles B and D
Step-by-step explanation:
When two lines are parallel, it implies the value of the angle between them is
. Thus the lines can not meet when extended continuously.
Alternate angles are two equal angles that lie on opposite sides of the transversal line. Alternate Interior Angles are a pair of equal angles on the inner side of two parallel lines.
Since lines DE and AB are parallel with alternate interior angles at B and D, then angles A and C with angles B and D are alternate interior angles.
i.e < A = < C (alternate interior angle property)
<B = < D (alternate interior angle property)
George's cost per day is
... c = 30 + 0.18m
We want c < 55, so we can write
... 30 + 0.18m < 55 . . . . . your inequality
_____
Here is the solution to the inequality
... 0.18m < 25
... m < 25/0.18
... m < 138.9
George must drive less than 138.9 miles that day.
Answer:
36
Step-by-step explanation:
Here is the correct and complete question: The units digit of a two-digit number is twice the tens digit. If the digits are reversed, the new number is 9 less than twice the original number. What is the original number?
Lets assume the original number be"10y+x". (x is unit digit and y is 10th digit)
∴ if number is reversed then resulting number be "10x+y".
As given: x= 2y
and 
Now, solving the equation to get original number.

Distributing 2 to 10y and x, then opening the parenthesis.
⇒ 
subtracting by (2x+y) on both side.
⇒ 
subtituting the value of "x", which is equal to 2y.
∴ 
⇒ 
subtracting both side by (16y-9)
⇒ 
cross multiplying
We get, 
y=3
∵x= 2y

∴ x= 6
Therefore, the original number will be 36 as x is the unit number and y as tenth number.
-2x + 4.4 = 23.8
Subtract 4.4 from both sides
-2x = 19.4
Divide both sides by-2:
X = -9.7
Answer: C. -9.7