Respuesta :
Answer:
Addition property of equality:
if a =b then; a + c= b + c
Subtraction property of equality:
if a =b then; a - c= b - c
Substitution property of equality:
If x =y then, x substituted in for y in any equation and y can be substituted for x in any equation.
Multiplication property of equality:
if a =b then; [tex]a \times c = b \times c[/tex]
Division property of equality:
if a =b then; [tex]\frac{a}{c} =\frac{b}{c}[/tex]
Commutative property of addition
a + b = b+ a
Given the system of equation:
[tex]4x + 3y = 25[/tex] ......[1]
[tex]2x-5y = 19[/tex] .....[2]
According to Multiplication property of equality;
Multiply equation [2] by -2 to both sides we get;
[tex]-4x + 10y = -38[/tex] ......[3]
Using Commutative property of addition;
Add equation [1] and [3] we have;
[tex]4x + 3y +(-4x+10y) = 25+(-38)[/tex]
[tex]13y = -13[/tex]
By division property of equality:
Divide by 13 both sides we get;
[tex]y = -1[/tex]
using Substitution property of equality:
Substitute the value of y in equation [1], we get;
[tex]4x+3(-1) = 25[/tex]
[tex]4x -3= 25[/tex]
By Addition property of equality:
Add 3 to both sides we get;
[tex]4x = 28[/tex]
Simplify:
x = 7