Use substitution to solve y=4x+5 2x+y=17

Mathematics · High School · Thu Feb 04 2021

Answered on

Given the equation:

y = 4x + 5

2x + y = 17

Solve using substitution.

Solution:

In order to solve the equation using substitution, we simply needed to substitute the value of  y from the first equation to the value of y for the 2nd equation.

2x + y = 17

2x + (4x + 5) = 17

Combine like terms and solve for x.

2x + (4x + 5) = 17

6x + 5 = 17

Trnaspose 5 to the other side of the equation, hence it must be taken to note that in transposing a number, the sign changes.

6x = 17 - 5

6x = 12

Divide both sides by 6 in order to determine the value of x.

6x/6 = 12/6

x = 2

Substitute the value of x to the first equation in order to determine the value of y.

y = 4x + 5

y = (4)(2) + 5

y = 8 + 5

y = 13

Final answer:

x = 2

y = 13