Answer:
x = 1 + sqrt(89) or x = 1 - sqrt(89)
Step-by-step explanation:
Solve for x:
(x - 9) (x + 7) = 25
Expand out terms of the left hand side:
x^2 - 2 x - 63 = 25
Add 63 to both sides:
x^2 - 2 x = 88
Add 1 to both sides:
x^2 - 2 x + 1 = 89
Write the left hand side as a square:
(x - 1)^2 = 89
Take the square root of both sides:
x - 1 = sqrt(89) or x - 1 = -sqrt(89)
Add 1 to both sides:
x = 1 + sqrt(89) or x - 1 = -sqrt(89)
Add 1 to both sides:
Answer: x = 1 + sqrt(89) or x = 1 - sqrt(89)
Just write them the on the other side the exact same way that they are on the Y coordinate hope this helps:)
1. consider one angle of a (convex) heptagon. From that angle you can construct 7-3=4 diagonals. (-3 because we cannot create diagonals with the adjacent vertices and the angle itself )
2. 4 diagonals create 5 triangular regions. (check the picture)
3. So the sum of the measures of the interior angles of the heptagon is 180°*5=900°.
4. The measure of the remaining 7th interior angle is 900°-(120+150+135+170+90+125)°=110°.
5. The largest exterior angle is when the interior angle is the smallest.
6. The smallest interior angle is 90°, so the largest exterior angle is 180°-90°=90°
Answer: 90°
Answer:
Let's define the cost of the cheaper game as X, and the cost of the pricer game as Y.
The total cost of both games is:
X + Y
We know that both games cost just above AED 80
Then:
X + Y > AED 80
From this, we want to prove that at least one of the games costed more than AED 40.
Now let's play with the possible prices of X, there are two possible cases:
X is larger than AED 40
X is equal to or smaller than AED 40.
If X is more than AED 40, then we have a game that costed more than AED 40.
If X is less than or equal to AED 40, then:
X ≥ AED 40
Now let's take the maximum value of X in this scenario, this is:
X = AED 40
Replacing this in the first inequality, we get:
X + Y > AED 80
Replacing the value of X we get:
AED 40 + Y > AED 80
Y > AED 80 - AED 40
Y > AED 40
So when X is equal or smaller than AED 40, the value of Y is larger than AED 40.
So we proven that in all the possible cases, at least one of the two games costs more than AED 40.