Do You Know How? In 4-6 solve each system using substitution. a y=(1)/(2)x+4 x-y=8 5. 3.25x-1.5y=1.25 13x-6y=10 6 y-0.8x=0.5 5y-2.5=4x

4. To solve the system of equations using substitution, we can substitute the expression for y from the first equation into the second equation: Substituting the expression for y into the second equation, we get: Simplifying the equation, we have: Adding 4 to both sides, we get: Multiplying both sides by 2, we find: Now, we can substitute the value of x back into the first equation to find the value of y: Therefore, the solution to the system of equations is and .5. To solve the system of equations using substitution, we can solve one equation for one variable and then substitute it into the other equation.Let's solve the first equation for x: Now, we can substitute this expression for x into the second equation: Simplifying the equation, we have: Multiplying both sides by 3.25, we get: This equation is not true, which means there is no solution to the system of equations.6. To solve the system of equations using substitution, we can solve one equation for one variable and then substitute it into the other equation.Let's solve the first equation for y: Now, we can substitute this expression for y into the second equation: Simplifying the equation, we have: This equation is true for all values of x, which means the system of equations has infinitely many solutions.