Question

Once you have a single variable isolated in one of the two equations in a system, the second step of using substitution to solve the system of equations is to

Answer 1

ok so if you were to use this 2x+7=21
first you would say im finding the x then -7 from both sides so 2x=14 and divide it by two and get 7

Answer 2

is that what you are meaning

Answer 3

So would i substitute the expression equal to the solved variable into its original equation?

Answer 4

give me a equation that has to do with this plz

Answer 5

Once you have a single variable isolated in one of the two equations in a system, the second step of using substitution to solve the system of equations is to __________.
A.
solve for the second variable in the other equation
B.
solve for the second variable in the same equation
C.
substitute the expression equal to the solved variable into the other equation
D.
substitute the expression equal to the solved variable into its original equation

Answer 6

@SolomonZelman

Answer 7

thats the question ^^^^

Answer 8

I think C, because what you are doing is

(my own example)

y=2x+1
2x+2y=7

2x+2(2x+1)=7

Answer 9

thank you what about this one?

Answer 10

In the system –12c + 3d = 6 and –3c + 6d = –9, which expression could you use for substitution?

Answer 11

thanks for helping @SolomonZelman

Answer 12

Do yuo have the choices?

Answer 13

A. d=-1/2c-3/2 B.c=-2d+3 C.c=1/4d-1/2 D. d=4c-2