164k views
1 vote
What is the y-intercept of the equation 3y + 2x =-21?

User Aleh Douhi
by
3.8k points

2 Answers

2 votes

Answer: -7

Explanation: To identify the y-intercept of the line, we would first convert the equation to slope-intercept form.

In slope-intercept form or y = mx + b form, the y

is by itself on the left side of the equation.

So our first task in this problem is to get y by itself on the left side of the equation and we do that by first subtracting 2x from both sides to get 3y = -2x - 21.

Notice that I put the x term first on the right side of the equation and then the number because in y = mx + b form, the x term comes first on the right side of the equation.

Continuing on, to get y by itself we would

divide both sides by 3 to get y = -2/3x - 7.

Now our equation is written in slope-intercept form and

we can identity that the y-intercept of this line is -7.

User Darshan Sawardekar
by
4.2k points
5 votes

In slope-intercept form, we can classify the following values.

m = slope

b = y-intercept

Turn the equation into slope-intercept form (y = mx + b).

3y + 2x = -21

~Subtract 2x to both sides

3y + 2x - 2x = -21 - 2x

~Simplify

3y = -21 - 2x

~Divide 3 to both sides

3y/3 = -21/3 - 2/3x

~Simplify

y = -7 - 2/3x

~Put into correct order

y = -2/3x - 7

So, the y-intercept is -7

Best of Luck!

User Ghalib
by
4.0k points