Question

5x-9y=7
7y-3x= -5

Answer 1

solve?

Answer 2

5x - 9y =7
-3x + 7y =-5

we can either solve for x or y, lets choose x. multiply both the top equation by 3 and the bottom equation by 5 to get the common factor of 15. Do that first.

Answer 3

ok

Answer 4

you mean -3?

Answer 5

and i would say this is a substitution problem solve for one of the variables in one of the equations, and plug it into the other equation

Answer 6

you are correct

Answer 7

@NickR you do not need to multiply it by -3 and substitution is just another way to solve it.

Answer 8

if you multiply it by just 3 the top you will get 15x and bottom by 5 to get -15x and then you just add them to get rid of it.

Answer 9

idk for me substitution is easier, and realize that now my bad

Answer 10

maybe substitution will be easier for you @bev199 so I will you show that way then.

Answer 11

thank you

Answer 12

correct me if im wrong but 5x-9y=7
-5x to both sides= -9y=-5x+7
divide by -9 both sides y=(5/9)x-(7/9)

Answer 13

yes sorry, I was in a rush so I made a mistake for not making the 7 to be -7, thankyou for pointing out my mistake.

1) 5x - 9y =7
2) -3x + 7y =-5

so rearrange the first equation in terms of x or y, I'll choose y.
5x - 9y = 7
5x - 7 = 9y
y=5/9x - 7/9

we can now substitute y=5/9x - 7/9 into the second equation as y.
-3x + 7y = -5
-3x + (5/9x - 7/9) = -5
I'll let you do the rest from here, you just have to expand, collect like terms and solve for x.
when you get the x value substitute it back into either of the equations and solve to get your y-value.

Answer 14

thanks guys

Answer 15

np glad to help

Answer 16

can you help me with one more problem NickR