Question
15 is the same as the product of 3 and a number. Which equation models this sentence?
15=3x
15=x-3
15=3+x
15=x divided by 3
Answer:
<h2>
15=3x</h2>
Step-by-step explanation:
15 = 3x
x = 15 : 3
x = 5
.........................
check
15 = 3 * 5
15 = 15
the answer is good
4, 5, and 7 are mutually coprime, so you can use the Chinese remainder theorem right away.
We construct a number
such that taking it mod 4, 5, and 7 leaves the desired remainders:

- Taken mod 4, the last two terms vanish and we have

so we multiply the first term by 3.
- Taken mod 5, the first and last terms vanish and we have

so we multiply the second term by 2.
- Taken mod 7, the first two terms vanish and we have

so we multiply the last term by 7.
Now,

By the CRT, the system of congruences has a general solution

or all integers
,
, the least (and positive) of which is 27.
d) x=-12 because x/-3=4 can be rearranged as x=4x-3 so x=-12