231k views
3 votes
If you were to solve the following system by substitution, what would be the best

variable to solve for and from what equation?
2x+8v=12
3r- 8v=11

If you were to solve the following system by substitution, what would be the best-example-1
User NVO
by
6.2k points

2 Answers

5 votes

Answer:

x, In the first equation.

Explanation:

User Rian Rizvi
by
7.2k points
4 votes
To solve the two equations simultaneously using the substitution method we need to rearrange one of the equation to make either
'x' or
'y' the subject.

We can try in turn rearranging both equations and see which unknown term would have been easier to solve first

Equation
2x+8y=12

Making
'x' the subject

2x=12-8y , dividing each term by 2

x=6-4y⇒ (Option 1)

Making
'y' the subject

8y=12-2x, multiply each term by 8 gives

y= (12)/(8) - (2)/(8)x⇒ (Option 2)

Equation
3x-8y=11
Making
'x' the subject

3x=11+8y, divide each term by 3

x= (11)/(3)+ (8)/(3)y ⇒ (Option 3)

Making
'y' the subject

8y=3x-11, divide each term by 8

y= (3)/(8)x- (11)/(8) ⇒ (Option 4)

From all the possibilities of rearranged term, the most efficient option would have been the first option, from equation
2x+8y=12 with
'x' as the subject,
x=6-4y





User WalterBeiter
by
7.5k points