Question

please help

100 is 80% of what number?

Answer 1

@UnknownRandom are u sure

Answer 2

That seems weird doesn't it?

Answer 3

yes hahha @UnknownRandom

Answer 4

It's right though. I actually had to check to make sure. Here is a site that might help. http://www.mathsisfun.com/percentage.html

Answer 5

I mean kit makes sense

Answer 6

can you hellp me with this one also?

Solve the system of equations
-7x − 8y = -8
-6x − 9y = -8

Answer 7

Maybe. Give me a min.

Answer 8

I'll let @thu1935 help you.

Answer 9

call x the number.
100 = 80% of x -> 100 = 80*x/100 -> 8x = 1,000 -> x = 1,000/8 = 125

Answer 10

@thu1935 thank you I need help with this next problem


Solve the system of equations
-7x − 8y = -8
-6x − 9y = -8

Answer 11

@thu1935 Thanks for the help. I thought something seemed wrong.

Answer 12

so what would Y be?

Answer 13

I can't remember how to do any of this right now. @mathslover Can you help with this.

Answer 14

Sorry I went brain dead. Here is a good resource http://www.purplemath.com/modules/systlin5.htm

Answer 15

-7x − 8y = -8 --------(1)
-6x − 9y = -8 --------(2)

In Equation 1 :

-7x = 8y - 8
x = \(\cfrac{8y-8}{-7}\)

Just put this value in equation 2 and solve for y and then for x

Answer 16

It is called substitution method.

Answer 17

@mathslover where would * go in the second problem

Answer 18

*8

Answer 19

-7x - 8y = -8 (times 6) --> -42x - 48y = -48
- 6x - 9y = -8 (times -7) --> 42x + 63y = 56
Add up the 2 equations --> 15y = 8 -> y = 8/15
Replace y by 8/15 in the first equation to get x.
-7x - 64/15 = -8
-105x - 64 = -120 --> 105*x = 56 -> x = 56/105

Answer 20

thank you all

Answer 21

Sorry I couldn't help more. I have been doing too much homework. Have a good night!