Question

Solve the following system of equations by linear combination:

3x + 2y = 7
y = x – 4

(3, –1)
(2, 6)
(–1, 3)
(6, 2)

Answer 1

Use substitution

Answer 2

Substitution?

Answer 3

Yes, like what u did with the x in the last question

Answer 4

This one isn't hard since they have already solved for y. Now plug in x-4 for y in the first equation. You get ... 3x + 2(x-4)=7. Now expand the paranthesis by distributing the 2 and we get 3x + 2x-8=7. Add like terms to get 5x-8=7 we're solving for x so move 8 to the other side and it becomes 5x=7+8 and that becomes 5x=15. divide both sides by 5 and get x = ?. Plug x into the second equation to get y...so y= ? - 4

Answer 5

what do i substitute?

Answer 6

The value of y into the first equation

Answer 7

is it A?

Answer 8

substitute x -4 for y in the first equation

Answer 9

3x + 2-4=7? @Tay003

Answer 10

3x + 2(x-4) =7

Answer 11

so whats the answer 0-0?

Answer 12

im confused, are there more steps? @Tay003

Answer 13

if you distribute you get 3x +2x -8=7 Always combine like terms so it 5x = 15 divide by 5 and you get the x value

Answer 14

so 15/5?

Answer 15

thats three so the first choice?

Answer 16

yup :)