Question

How do you solve x+y+3 and 2x+3y=9?

Answer 1

there is one error that is x+y=3 not +3

x+y=3

y=3-x

2x+3(3-x)=9 [y=3-x]

2x+9-3x=9

2x-3x=0

-x=0

X=0

y=3-x

y=3-0=3

check

2*0+3*3=9

0+9=9

9=9

LHS=RHS

Answer 2

To solve this equation we need to apply substitution method :

x + y + 3   =>   x + y = 3                    -------- (1)

2x + 3y = 9                                       -------- (2)

From eq (1)

x = 3 - y

Now substituting value of x in eq (2)

2x + 3y = 9

2( 3 - y ) + 3y = 9

6 - 2y + 3y = 9

6 + 3y - 2y = 9

6 + y = 9

y = 9 - 6

y = 3

Now substituting the value of y in eq(1)

x + y = 3

x + 3 = 3

x = 3 - 3

x = 0

∴ Value of y is 3 and value of x is 0