Answer:
1680
Step-by-step explanation:
Considering repeatition is not allowed.
We can use permutation to reach to the required answer.
Consider four digits to be placed in four boxes. Now for the number to be odd, unit digit must be odd. Therefore, unit digit can only be filled by 1, 3, 5,7, or 9. That is 5 ways. Now, other three boxes can be filled with 8, 7 and 6 ways respectively.
Therefore, Total numbers = 5×8×7×6 = 1680
Answer:
15
Step-by-step explanation:
Using substitution method
from the first equ
2x+y=-1
y= -1-2x --------(3)
put equ 3 into equ 2
3x -1-2x=6
3x-2x=6+1
x =7
put x+7 into equ 1
2(7) + y = -1
14 + Y =-1
y= -1-14
y=-15
so
x=7 and y=-15<span />
Step-by-step explanation:
see the answer in the pic
The answer
<span>the true answer is A) 4x^2+52x+165=320; x = 2.5
proof:
since </span><span>they want to limit its area to 320 in^2
x must be equal 2.5, because </span>4.(2.5)^2+52(2.5)+165= 25+130+165=320;
the main rule of the area of a triangle is
A= (base x height )/2
let be b the base and h the height
so h=20- 6b
so 50= b x( 20-6b) /2, implies 100/b = 20 - 6b
if b=x, we have 100= 20x -6x² this is equivalent to 6x² - 20x = -100
so the answer is
<span>D) None of the choices are correct.
</span>
<span>the largest dimensions that can be used for the fountain are
</span>
<span>B) x^2+8x+16=800
C) x^2+16=800
</span>
proof
x^2+8x+16=x^2+8x+4², 4² is the area of the square fountain, and x^2+8x should be the remaining of the area, t<span>he total space that the fountain and sidewalk can use is 800, it is less than 800 ft^2.
</span>Use the same method for. x^2+16=800