Question

2x - y = 5
x + 3y = 7

What is the value of the system determinant?


5
6
7

Answer 1

x=7-3y according to the bottom equation. Plug that in to the top equation to solve it

Answer 2

how do i plug it in??

Answer 3

If the equation is 2(x)-y=5
and x=7-3y
then 2(7-3y)-y=5
Does that make sense to you?

Answer 4

where did the x go

Answer 5

A drawing might help you
one minute

Answer 6

The second equation can be rearranged to make x equal to 7-3y. Because now we know x is equal to that, we can replace x in the first equation with the rearranged equation. This is called substitution