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Hi,please help me.with this question im.confuse. please help me with question 1c

Hi,please help me.with this question im.confuse. please help me with question 1c-example-1

2 Answers

4 votes
1c. 3x - 2y = 6
x = 5 - 2y

What they mean by substitution is that you need to put that x that they gave you into the x of the first equation to get y.

Right now it looks like this:
3x - 2y = 6

Now you have to put (5 - 2y) into the x of the equation.

3(5 - 2y) - 2y = 6

Now solve.
First distribute the 3.

15 - 6y - 2y = 6

Combine like terms.

15 - 8y = 6

Get rid of the 15 by subtracting it from both sides.

-8y = -9

Divide both sides by -8.

y = 1.125

Now put the y into the second equation.

x = 5 - 2(1.125)
x = 5 - 2.25
x = 2.75


x = 2.75
y = 1.125
User Koque
by
7.3k points
3 votes

3x-2y=6

x=5-2y

replace x in the 1st equation with x in the 2nd one so you get:

3(5-2y)-2y=6

15-6y-2y=6

15-8y=6

-8y=-9

y=1.125

x=5-2(1.125) = 5-(2.25)=2.75

check: 3(2.75)=8.25, 2(1.125)=2.25, 8.25-2.25 = 6

y = 1.125

x = 2.75




User Yenchi
by
7.4k points