Exponent rule : a^-x = 1/a^x
x^-9 * x^-2 =
1/x^9 * 1/x^2 = (when multiplying exponents with same base, add exponents)
1/x^(9 + 2) =
1/x^11
Answer:
( 8 , - 8) => x² - 55 = 9
( 4 , - 4) => 2x² - 32 = 0
(5 , - 5) => 4x² - 100 = 0
(11 , - 11) => x² - 140 = -19
( 3, - 3) => 2x² - 18 = 0
Step-by-step explanation:
1)
x = ( 4 , - 4)
2)
x = ( 5 , - 5 )
3)
x= ( 8 , - 8)
4)
x = ( 11 , -11)
5)
x = ( 3 , - 3)
7 + (x/8) in written form. I hope this helps! -Dan
The <em>correct answers</em> are:
5x²+70x+245 ≥ 1050; and
Yes.
Explanation:
Let x be the width of the tablet. Since the width of the TV is 7 inches more than the tablet, the width of the TV would be x+7.
The length of the TV is 5 times the width; this makes the length 5(x+7) = 5x+35.
The area of the TV would be given by
(x+7)(5x+35).
Since Andrew wants the area to be at least 1050, we set the expression greater than or equal to 1050:
(x+7)(5x+35) ≥ 1050
Multiplying this, we have:
x*5x+x*35+7*5x+7*35 ≥ 1050
5x²+35x+35x+245 ≥ 1050
Combining like terms,
5x²+70x+245 ≥ 1050
To see if 8 is a reasonable width for the tablet, we substitute 8 for x:
5(8²)+70(8)+245 ≥ 1050
5(64)+560+245 ≥ 1050
320+560+245 ≥ 1050
1125 ≥ 1050
Since this inequality is true, 8 is a reasonable width.
