Question

Solve the system of linear equations by substitution.

x + 4y = 30
y = −x + 9


The solution of the system is (___, ___).

Answer 1

Plug in -x+9 in for y and you should get (2,7)

Answer 2

hey! This was the only part of mathematics I ever enjoyed! So consider this both of our lucky days: Answer is : (2,7)

Explanation:

basically plug in Y to the first equation as sox + 4(-x + 9) = 30

x - 4x + 36 = 30- 3x = - 6

x = 2

then plug that in to Y!

Y = -(2) + 9

so Y = 7

and our answer is : (2,7)