Question

Solve system of equations.
2x-4y=10
7x-9y=12
Don't understand this at all.

Answer 1

with the help of one of these equation take out the value of x or y. for example 2x=10+ 4y. and then x=10+4y/2. now put the value of x in other equation and then find out the value of x and y by solving the equation.

Answer 2

2x + 4y = 10
2x = 10 - 4y
x = 10/2 - 4/2y
x = 5 - 2y
now sub 5 - 2y in for x in the other equation.
Do you understand what I did so far ?

Answer 3

Yes thank you

Answer 4

now you can solve for y by subbing in 5 - 2y in for x. Can you do that ?

Answer 5

Yes I got 3/5,-11/5

Answer 6

let me check....
7x - 9y = 12
7(5 - 2y) - 9y = 12 (distribute through the parenthesis)
35 - 14y - 9y = 12 (combine like terms)
35 - 23y = 12
35 - 12 = 23y
23 = 23y
y = 1
now sub 1 in for y
2x - 4y = 10
2x - 4(1) = 10
2x -4 = 10
2x = 10 + 4
2x = 14
x = 7
check...
2x - 4y = 10
2(7) - 4(1) = 10
14 - 4 = 10
10 = 10 (correct)
Something might be wrong because when I check it with the other equation, it doesn't equal......

Answer 7

@merchandize .....what did I do wrong...it checks out with one equation, but I can't get it to equal with the other equation when I check it.

Answer 8

@burhan101 ...can you come take a look at this please

Answer 9

I have 3 answer choices
(3/5,-11/5)
(-21/5, -23/5)
(-69/5,-47/5)

Answer 10

Let me do it the elimination way...hold on

Answer 11

2x - 4y = 10 -->(7)2x - 4y = 10
7x - 9y = 12 --> (-2)7x - 9y = 12
---------------
14x - 28y = 70 (result of multiplying by 7)
-14x + 18y = - 24 (result of multiplying by -2)
------------
- 10y = 46
y = - 46/10 = - 23/5

the answer is going to be (-21/5, -23/5)

Answer 12

(-21/5,-23/5) is the answer.