Question

Ahhhhh Blue Haired Cupcake Thrower is back! I'M ALMOST DONE WITH SCHOOL!
2x+4y=14
3x+12y=51
A. (-1, 12)
B. (-3, 5)
C. (-1, 3)
D. (-3, 20)

Answer 1

do you prefer substitution or elimination ?

Answer 2

I am back too.
we use the elimination rule again but at first we multiply the first equation by -3
-6x -12y = -42
3x + 12y = 51
sum them up
-3x = 9
x = -3
3 * -3 + 12y = 51
-9 + 12y = 51
12 y = 60
y = 5
Check:
-3 * -6 - 12 * 5 = -42
18 - 60 = -42
-42 = -42
Variant B(-3 5)

Answer 3

or substitution..
2x + 4y = 14 --- divide by 2
x + 2y = 7
x = -2y + 7
now sub -2y + 7 in for x in the other equation
3x + 12y = 51
3(-2y + 7) + 12y = 51
-6y + 21 + 12y = 51
-6y + 12y = 51 - 21
6y = 30
y = 5
now sub 5 in for y in either equation to find x
2x + 4y = 14
2x + 4(5) = 14
2x + 20 = 14
2x = 14 - 20
2x = - 6
x = -3

solution is : x = -3 and y = 5

Answer 4

either way you should arrive at the same answer....whichever it is easier for you to do

Answer 5

true. however in first order equations elimination is the simplest choice.