Question

4-9). Solve the following system of linear equations by elimination.
x+y=10
-x+y=4
what is x?
what is y?

Answer 1

2y = 14
y=7
x = 10-7
x=3

Answer 2

x+y=10
-x+y=4 cancel the -+(x)

2y=14 divide both side by 2.

y=7

substitue the value of y to the first eq.

x+7=10
x=10-7
x=3

sol.{x=3,y=7}

Answer 3

Good answer awarded to rawxX45 for detailed and lucid answer.

Answer 4

x+y=10
-x+y=4
solve for x
x=10-y substitute this to the second
-(10-y)+y=4
2y=14
y=7
x=10-7=3
Ans x=3, y=7