Question

5x+6y=7
-2x+y=21
substitution method

Answer 1

y = 2x + 21
plug this into 5x + 6y = 7
to give an equation in x
solve and sub this value in one of the original equatiuos to get y

Answer 2

The same method again.
take the 2nd one and give a result for y. It will go like this:
y=2x+21. Now go at the 1st one and when you see y put 2x+21.
It will go like this: 5x+6(2x+21)=7...... you will found x and then go at 2nd again and put the number that you found. Use the same method for all.

Answer 3

so x=-7?

Answer 4

y=126?

Answer 5

x=-7,right.
So,now you will go at y=2x+21 and whenever you see x you will put -7.
So we have : y= 2(-7)+21=-14+21=7
A(-7,7).

Answer 6

I think I get it... I just do not know why I am having a hard time with this..

Answer 7

I have another, I am going to try this one and let me know if I am correct.. if you do not care please

Answer 8

It's pretty easy. That's one of the 3 types that you can solution this type of exercices. The 2nd type it's to multiply the hole equation with a number that you can add from the other equation for have 0 on x or y. Then you can easy find the other. When I say it it's harder to understand it. Focus more at school :)

Answer 9

8x+5y=-4
-2x+y=10
8x+5(2x+10)=-4
x=-3
2(-3)+10=4+10=14
(4,-4)?

Answer 10

x=-3,that's right. Now you are going at -2x+y=10 and whenever you see x you will put -3. so we have : (-2)(-3)+y=10 => y=10-6 => y=4.
A(-3,4). Good job,you are going better. :)

Answer 11

thank you

Answer 12

No problem my friend.

Answer 13

This one is a little different, can you help with this one please?
7x-6y=-35
5x+48=y

Answer 14

7x-6(5x+48)=-35
x=-11
5(-11)+48=-7
y=-7

Answer 15

Correct! :)

Answer 16

Omg... Thank you!!