Question

Solve the system of equations: what is the x-value for the solution?
2x + 7y = 3 and x = 1 - 4y

A) -1
B)5
C)4
D)3

Answer 1

you want the x-value...so I would solve 1 of these equations for y...then plug it into the other equation

2x + 7y = 3
7y = 3 - 2x
y = 3/7 - 2/7x

this is y....so plug it into the second equation

x = 1 - 4y

replace "y" with what you GOT for y

x = 1 - 4(-2/7x + 3/7)

x = 1 + 8/7x - 12/7

get the 2 x's together

x - 8/7x = 1 - 12/7

-1/7x = -5/7

multiply both sides by -7

x = 35/7

x = 5

If i am not correct...anyone please correct me :)

Answer 2

2x + 7y=3, x = 1-4y
2(1-4y)+7y=3
2-8y+7y=3
2-1y=3
2-y=3
y=3/-2
y=-1

Answer 3

Thank you!

Answer 4

@Tanieshia right....if x = 5 like I said...then the y would = -1

you wanted the x number @ally44 correct? so that would be the 5 like I said

Answer 5

ok @ johnweldon, i got u since they already gave x i thought we were looking for y

Answer 6

lol no problem...now she would see how to solve for y as well :)

Answer 7

it's B

Answer 8

lol ok so she needed x and not y? ok my bad

Answer 9

johnweldon1993 can i have your views on this one pls

Answer 10

hmmm well the lines of symmetry would be you can fold it over and have the SAME shape...

so you can fold it in half...thats 1
you can fold it in half down...thats 2
you can fold it into a triangle shape 2 different ways...thats 4 now

hmm...anyone else add any? lol

Answer 11

thank you so much