The answer is bbc or if that’s not the answer the then it’s bbl THANK ME LATERRRR
4, 7 and 9 are mutually coprime, so you can use the Chinese remainder theorem.
Start with
Taken mod 4, the last two terms vanish and we're left with
We have 
, so we can multiply the first term by 3 to guarantee that we end up with 1 mod 4.
Taken mod 7, the first and last terms vanish and we're left with
which is what we want, so no adjustments needed here.
Taken mod 9, the first two terms vanish and we're left with
so we don't need to make any adjustments here, and we end up with 
.
By the Chinese remainder theorem, we find that any 
such that
is a solution to this system, i.e. 
for any integer 
, the smallest and positive of which is 149.
The correct answer is: [D]: " 7.2 units" .
_______________________________________________________
Explanation:
________________________________________________________
Use the Pythagorean theorem:
a² + b² = c² ;
in which: "6 units" and "4 units" equal the lengths of the right angle (formed by the rectangle); and "c" is the length of the diagonal of the rectangle, or the "hypotenuse", of the right triangle formed by the rectangle; We wish to solve for "c" ;
_______________________________________________
6² + 4² = c² ; Solve for "c" ;
↔ c² = 6² + 4² ;
= (6*6) + (4*4) ;
= 36 + 16 ;
= 52 ;
c² = 52 ;
Take the "positive square root" of each side of the equation; to isolate "c" on one side of the equation; and to solve for "c" ;
√(c²) = √52 ;
c = √52 ;
At this point, we know the 7² = 49 ; 8² = 64 ; so, the answer is somewhere between "7" and "8" ; yet closer to "7" ; so among the answer choices given;
The correct answer is: [D]: " 7.2 units" .
_________________________________________
However, let use a calculator:
c = √52 = 7.2111025509279786 ; which rounds to "7.2" ;
which corresponds to:
___________________________________________
Answer choice: [C]: " 7.2 units" .
___________________________________________
Use trigonometric ratios.
Use angle(19)
Adjacent side of angle measure 19 is X
The hypotenuse is 21.
Use the cosine
Cos(19)=x/21
Plug in calculator
(21)cos(19)=19.85
Round to the nearest tenth. Which means the 8 rounds up to 9.
Answer: 19.9
