a. The moduli are coprime, so you can apply the Chinese remainder theorem directly. Let

- Taken mod 3, the last two terms vanish, and
so we need to multiply by the inverse of 2 modulo 3 to end up with a remainder of 1. Since
, we multiply the first term by 2.

- Taken mod 4, the first and last terms vanish, and
. Multiply by the inverse of 3 modulo 4 (which is 3 because
), then by 2 to ensure the proper remainder is left.

- Taken mod 5, the first two terms vanish, and
. Multiply by the inverse of 2 modulo 5 (3, since
) and again by 3.


By the CRT, we have

i.e. any number
(where
is an integer) satisifes the system.
b. The moduli are not coprime, so we need to check for possible contradictions. If
and
, then we need to have
. This basically amounts to checking that if
, then we should also have
.



The last congruence conflicts with the previous one modulo 3, so there is no solution to this system.
Answer:
The first one is correct
The second one is 20years
The third one is £8820
Step-by-step explanation:
Y² + 16 = 212
<span>y</span>² <span>= 196 </span>
<span>y = -14 and 14</span>
You can try finding numbers that are close to what you think you can use for exaple lets say we want to find the answer to 54x34 you could multiply 50x30 to get an estimated answer