solve the system using elimination subsitution or matrix met

solve the system, using elimination, subsitution, or matrix methods.

7/3x + 5/4y = 4

10x-5y=42

(7/3)x + (5/4)y = 4-->(1)

10x-5y=42

=>2x-y =42/5

=>y =2x -(42/5) ------>(2)

substitute (2) in (1)

(7/3)x + (5/4)(2x -(42/5)) = 4

(7/3)x + (5/4)2x -((5/4)(42/5)) = 4

(7/3)x + (5/2)x = 4+(21/2)

x((7*2)+(3*5))/(3*2) =(8+21)/2

x*29/6 =29/2

x =(29/2)*(29/6)

x =3

put x =3 in (2)

y =2*3 -(42/5)

y=(30-42)/5

y =-12/5

x =3, y =-12/5 is the solution by substitution method