Question

Use the substitution method to solve the following system of linear equations:

x + y = 3
x = y – 7

A.
The solution is (–2, 5).

B.
The solution is (4, 1).

C.
There are an infinite number of solutions.

D.
There is no solution.

Answer 1

x = y – 7
means x "is the same" as y-7

replace x in the first equation with y-7. you get a new equation.
can you write down the new equation?

Answer 2

Substitute 'y - 7' for 'x' in the 1st equation:

x + y = 3

y - 7 + y = 3

Combine like terms:

2y - 7 = 3

Add 7 to both sides, what's 3 + 7?

Answer 3

10

Answer 4

@iGreen. is the answer A?