Question

Select the correct answer.

To solve this system of equations using substitution, what could be substituted in place of y in the first equation?
4x=5-2y
y-2x=7

A 7-2x
B. 4x-5
C. 5-4x/2
D. 2x + 7

Answer 1

C

when doing substitution,you must make one a subject,which is y in this case.To make y the subject,you must move -2y to 4x to make the y positive,that leaves us with 2y+4x=5.Now move the 4x to 5 to make 2y=5-4x.Lastly,to make y the subject,divide both side by 2 to remove the 2 from the y, which leaves us with y=5-4x/2