Question

Select three equations that could represent a step in solving this system using the substitution method. 4x+y = 6 x = 8 0.52 1x 0.00

Answer 1

Only the first and the last equations are correct

Here, we want to select three equations that could represent a step in solving the system of linear equations by substitution

We consider the given options one after the other

a) 4(8) + y = 6

By substituting the second equation in the first, we have this. So this is correct

b) y = 18

This is incorrect. From A, if we proceed to follow through the solution, we get that y = 6-32 = -26

c) 12x + y = 6

This is incorrect. We already have an expression in the first equation. This is similar albeit the difference in the coefficeint of x. We cannot have the same equation and as such, this cannot be correct

d) y = -24

This is not correct

By solution, y is -26 (6-32)

e) y + 32 = 6

This is correct

It is what we get by directly evaluating the first equation