Question

Question 2.2. Solve the given system, using the substitution method.

y = 3x – 7
6x – 2y = 12

(Points : 1)
(14, 12)
(12, 14)
There is no solution.
There are an infinite number of solutions.




Question 3.3. Solve, using the substitution method.

5x + 2y = 7
y = x – 7

(Points : 1)
(7, 0)
(3, –4)
(0, –7)
(–1, –8)

Answer 1

in
6x – 2y = 12
can you substitute y = 3x – 7 and find x ?

Answer 2

y=4x

Answer 3

6x – 2y = 12 becomes
6x - 2(3x - 7) = 12
6x - 6x + 14 = 12
14 = 12

IMPOSSIBLE

so there's no solution, right?

Answer 4

ok

Answer 5

now can you do the same for the second one Q.3.3 ?
Or, are you after the straight answer or want to learn how to do it ?

Answer 6

i want to learn how to do it.

Answer 7

great!!!
substitute
y = x – 7
in
5x + 2y = 7

and u get
5x + 2(x-7) = 7

can u continue from here?

Answer 8

yeah

Answer 9

5x+2(-6)=7
5x-12=7

is that right.

Answer 10

no dear ;)
2(x-7) = 2x - 14
can u continue?

Answer 11

yea

Answer 12

14x=-12y

Answer 13

I'll write down
5x + 2(x-7) = 7
5x + 2x -14 = 7 , add +14 to both sides
5x + 2x - 14+14 = 7+14 , -14+14 = 0, 5x+2x = 7x, 7+14 = 21
7x = 21 , divide both sides by 7
7x/7 = 21/7
x = 3

now y = x - 7 - 3 - 7 = -4

so the answer is 3, -4

do u understand how we got it?

Answer 14

yeah thank you

Answer 15

welcome
I'd recommend u first try to strengthen ur skill on solving simple problems like
3(x + 11) = ?
and -7(2 - x) = ?

Answer 16

ok