The given is that A B C D <span>x 4 = D C B A
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Possible values of A are 1 or 2. It can't be 1 since the </span><span> </span><span>final result A is in unit place and 1 is not possible when we multiply any number by 4
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2 B C D x </span><span>4 = </span><span>D C B 2</span>
It is clear above, that D = 8
2 B C 8 x <span>4 = </span><span>8 C B 2</span>
Possible values of B should be 1 or 2
We try B=1
2 1 C 8 x <span>4 = </span><span>8 C 1 2
</span>To find for C, you can use the equation:
(2000+100+10C+8) x 4 = 8000+100C+10+240C = 432-12 = 420
Therefore,
C = 7
So, the number is 2178.
Im not sure, when in doubt pick C
#2 is answer 4, #3 is answer 3, #4 is answer 4. The answer to #5 is 6xy if it is a possibility.
Answer:
x = - 2, x = - 
Step-by-step explanation:
Given
5x² + 1 = - 13x - 5 ( add 13x - 5 to both sides )
5x² + 13x + 6 = 0
Consider the factors of the product of the x² term and the constant term which sum to give the coefficient of the x- term
product = 5 × 6 = 30 and sum = 13
The factors are 10 and 3
Use these factors to split the x- term
5x² + 10x + 3x + 6 = 0 ( factor the first/second and third/fourth terms )
5x(x + 2) + 3(x + 2) = 0 ← factor out (x + 2) from each term
(x + 2)(5x + 3) = 0
Equate each factor to zero and solve for x
x + 2 = 0 ⇒ x = - 2
5x + 3 = 0 ⇒ 5x = - 3 ⇒ x = - 