Question

Questloll 23.
A number 4 more than a given number lies​

Answer 1

Answer:

To solve the problem, write the following system of 2 linear equations corresponding to the definition:

x = y + 4

3x + 1 = 4y

Re-write it in canonical form:

x - y = 4

3x - 4y = -1

Next, solving this system of linear equations either manually, or using online System of Linear Equations Solver (http://examn8.com/SystemOfEquations.aspx) gives the answer:

x = 17 (the larger number)

y = 13 (the smaller number)

Note: to solve the System of Linear Equations I recommend to use the most universal and computationally-efficient method shown below:

Systen of 2 Linear Equations with 2 unknown variables X and Y in canonical form:

A1X+B1Y=C1

A2X+B2Y=C2

The Solution:

First, calculate the determinant:

determinant = A1*B2-A2*B1

Find X and Y directly provided that determinant is not 0 (otherwise, there is no valid solution for X and Y):

X = (B2*C1-B1*C2) / determinant

Y = (A1*C2-A2*C1) / determinant