Question

Reasoning Solve the system of linear equations using substitution. Use pencil and paper. Which
expression would be easier to substitute into the other equation, in order to solve this problem?
Explain your reasoning.
X = 4y - 9
X + 4y = 7
The solution is
(Simplify your answer. Type an ordered pair.)

Answer 1

Answer:

Since the first equation x is equal to 4y - 9, it is easier to substitute 4y - 9 in for x in the second equation.

x = -1    y = 2

Step-by-step explanation:

Since the first equation x is equal to 4y - 9, it is easier to substitute 4y - 9 in for x in the second equation.  That would give you

4y - 9 + 4y = 7

8y - 9 = 7

8y = 16

y = 2

x = 4y - 9 = 4(2) - 9 = 8 - 9 = -1

It is always a good idea  to check and see if your results satisfy the two equations