7) Solve the following system of equations below algebraically using substitution.

8x - 4y = 7

x + y = 8

x = 3.25

y = 4.75

Step-by-step explanation:

In order to Solve the following system of equations below algebraically using substitution method we say that;

let;

8x - 4y = 7 ... equation 1

x + y = 8 ... equation 2

from equation2

x + y = 8 ... equation 2

x = 8 - y ... equation 3

substitute for x in equation 1

8x - 4y = 7 ... equation 1

8 (8-y) - 4y = 7

64-8y-4y=7

64-12y=7

collect the like terms

64-7 = 12y

57 = 12y

divide both sides by the coefficient of y which is 12

57/12 = 12y/12

4.75 = y

y = 4.75

put y = 4.75 in equation 3

x = 8 - y ... equation 3

x = 8 - 4.75

x = 3.25

to check if your answer is correct, put the value of x and y in either equation 1 or 2

from equation 2

x + y = 8 ... equation 2

3.25 + 4.75 = 8

8=8 ... proved