Answer:
( [tex]\frac{20}{7}[/tex], - [tex]\frac{12}{7}[/tex] )
Step-by-step explanation:
4x - 5y = 20 → (1)
2x + y = 4 → (2)
subtract 2x fro both sides in (2)
y = 4 - 2x → (3)
substitute y = 4 - 2x into (1)
4x - 5(4 - 2x) = 20 ( distribute parenthesis and simplify left side )
4x - 20 + 10x = 20
14x - 20 = 20 ( add 20 to both sides )
14x = 40 ( divide both sides by 14 )
x = [tex]\frac{40}{14}[/tex] = [tex]\frac{20}{7}[/tex]
substitute this value into (3)
y = 4 - 2([tex]\frac{20}{7}[/tex] ) = [tex]\frac{28}{7}[/tex] - [tex]\frac{40}{7}[/tex] = - [tex]\frac{12}{7}[/tex]
solution is ( [tex]\frac{20}{7}[/tex] , - [tex]\frac{12}{7}[/tex] )
