Question

Alright, guys, I'm confused.

J + S = 150
2J + 3.5S = 405

Solving for J

Answer 1

you have 2 methods :
elimination, substitution.
which one u wanna use ?

Answer 2

I thought,

S = 150 - J <-- sub

2J + 3.5(150 - J) = 405
2J + 525 - 3.5J = 405
-1.5J = -120
J = 80, is that right?

Answer 3

yes, correct.

Answer 4

any doubts

Answer 5

No doubts.

Answer 6

good :)

Answer 7

@hartnn , got a question.

If I had, 2x + y = 3, and I wanted to put in y = mx + b
I would say: y = 2x + 3, or would the 2x be negative because I switched it's side?

Answer 8

since u switched side its -2x

Answer 9

a better way to explain that is
2x+y=3
subtracting 2x from both sides
2x-2x+y= -2x +3
i subtracted because we need to do inverse operation, since 2x was added to y,
to isolate y, you subtract it.