Calcule o valor numerico dessa expressão: a+b=7 2x+y=8
1 answer:
You might be interested in
Answer:
Step-by-step explanation:
Answer:
D (7, 0.5)
Step-by-step explanation:
The equations must be interpreted to be ...
- y = -1/2x +4
- y = 1/2x -3
A graph shows the solution to be (7, 0.5), matching selection D.
___
You can add the two equations together to get ...
(y) +(y) = (-1/2x +4) + (1/2x -3)
2y = 1 . . . . . simplify
y = 1/2 . . . . .divide by 2
It can be convenient to use the second equation to find x.
1/2 = 1/2x - 3
1 = x - 6 . . . . . . multiply by 2
7 = x . . . . . . . . . add 6
The solution is (x, y) = (7, 0.5). . . . . matches selection D.
