Answer:
see explanation
Step-by-step explanation:
(1)
y = 5x - 7x , that is
y = - 2x ( divide both sides by - 2 )
x = - [tex]\frac{1}{2}[/tex] y
(2)
mx - r = y ( add r to both sides )
mx = y + r ( divide both sides by m )
x = [tex]\frac{y+r}{m}[/tex]
(3)
2x + 3y = 10 ( subtract 2x from both sides )
3y = 10 - 2x ( divide both sides by 3 )
y = [tex]\frac{10-2x}{3}[/tex]
(4)
5x - 3y = 4 ( subtract 5x from both sides )
- 3y = 4 - 5x ( divide both sides by - 3 )
y = [tex]\frac{4-5x}{-3}[/tex] ( multiply numerator/ denominator by - 1 , to 'tidy up' )
y = [tex]\frac{5x-4}{3}[/tex]
