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9 votes
Find the solution of y = 4x + 2 for x = -5.

A.
(-5, -18)


B.
(-5, 22)


C.
(-18, -5)

User Yukio
by
3.9k points

1 Answer

8 votes

Answer: THE ANSWER WOULD BE A. (-5, -18)

Notice how y=4x%2B2 is in slope-intercept form y=mx%2Bb where m is the slope and b is the y-intercept.

So this shows us that the slope is m=4 and the y-intercept is b=2 which is the point (0,2)

You can always plot an equation like this to find intercepts

and slope. Each point requires an x and a y. My

way is to make x+=+0 and find y,

then I make y+=+0 and find x

y+=+4x+%2B+2

y+=+4%2A0+%2B+2 solve for y

y+=+2

the point is (0,2)

then,

0+=+4x+%2B+2 solve for x

subtract 2 from both sides

4x+=+-2

x+=+-%281%2F2%29

the point is (-%281%2F2%29,0)

Once you have any two points, you can draw the line by connecting them

When the equation is in the form

y+=+mx+%2B+b

m = slope

b = y-intercept

So, your equation y+=+4x+%2B+2

m+=+4 (slope)

b+=+2 (y-intercept)

Explanation:

Solve for the first variable in one of the equations, then substitute the result into the other equation.

Point Form: (

5

,

18

)

Equation Form: x

=

5

,

y

=

18

User RikSaunderson
by
4.5k points