Solve the following system by the substitution method x y
Solve the following system by the substitution method. x + y = 5 y = x^2 - 7 Select the correct choice below and, if necessary, fill in the answer box to The solution set is {}. (Type an ordered pair. Use a comma to separate answers as needed. There is no solution.
Solution
Given x+y=5 and y=x2-7
From x+y=5
y=5-x
Substitute y=5-x in y=x2-7
y=x2-7
5-x=x2-7
x2-7-5+x=0
x2+x-12=0
(x+4)(x-3)=0
x+4=0 or x-3=0
x=-4 x=3
Therefore,x=-4,3
Substitute x=-4 in y=5-x
y=5-(-4)=5+4=9
Substitute x=3 in y=5-x
y=5-3=2
When x=-4,y=9
When x=3,y=2
Therefore, the solution set is {(3,2),(-4,9)}
The Option A is the correct one.
