Solving for y

Q:  Use the equation y = -2x + 1.  Complete each solution:

(a) (0, __ )

(b) (-5, __ )

(c) (20, __ )

(d) (-68, __ )

A:  So, we have an equation y = -2x + 1 and we are given a bunch of points to complete.  Notice that these are (x, y) points.  In all of the problems, we were given the x value but we need to find the y value.  Therefore, we are going to plug in the given number for x, then solve for y!

(a) (0, __ )

Plug in 0 for x:

y = -2x + 1

y = -2(0) + 1

y = 0 + 1

y = 1

(b) (-5, __ )

Plug in -5 for x:

y = -2x + 1

y = -2(-5) + 1

y = 10 + 1

y = 11

(c) (20, __ )

Plug in 20 for x:

y = -2x + 1

y = -2(20) + 1

y = -40 + 1

y = -39

(d) (-68, __ )

Plug in 0 for x:

y = -2x + 1

y = -2(-68) + 1

y = 136 + 1

y = 137

And, there you go!  You have all of the missing pieces.

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