STEM Gender Equality | Join us on ZOOM | Spreading Mathematical Happiness

MathsGee is free of annoying ads. We want to keep it like this. You can help with your DONATION

0 like 0 dislike
22 views
$$4x + y = 1 \\ 2x + 2y = -4$$

In this system of equations above, what is the value of x?
| 22 views

0 like 0 dislike
4x + y = 1                    (i)

2x + 2y = -4                (ii)

Multiplying (i) by 2 gives: 8x + 2y = 2                (iii)

(iii) - (ii) gives 6x = 2 - (-4) = 6

This implies that x = 1

Substituting 6 for x in (i) gives: (4)(1) + y = 1

y = 1 - 4 = -3
by Silver Status (29,005 points)