# Solve the linear congruence 7x -= 13(mod 19)

Solve the linear congruence
$7x\equiv 13\left(\text{mod}19\right)$
You can still ask an expert for help

## Want to know more about Congruence?

• Questions are typically answered in as fast as 30 minutes

Solve your problem for the price of one coffee

• Math expert for every subject
• Pay only if we can solve it

casincal
Calculation:
Since $7x\equiv 13\left(\text{mod}19\right)$
In order to find an inverse of a modulo m, we look for a multiple of a that exceeds multiple of m by 1.
11.7=1(mod 19)
So, 11 is the inverse of 7 modulo 19.
Multiplying both sides by 11 shows that
11.7x = 11.13(mod 19)
so, 77 = 1(mod 19) and 143 = 77(mod 19)