Ask your own question, for FREE!
Mathematics 8 Online
OpenStudy (anonymous):

HElp me please!!!!!!!!

jimthompson5910 (jim_thompson5910):

do you know how to graph `y = -2x - 2` ?

jimthompson5910 (jim_thompson5910):

y = -2x - 2 is a linear equation. Ie, a straight line

jimthompson5910 (jim_thompson5910):

if x = 0 for instance, then y is... y = -2x - 2 y = -2*0 - 2 ... replace x with 0 y = 0 - 2 y = -2 so we have the point (0,-2). Do you see how I got this?

jimthompson5910 (jim_thompson5910):

now use x = 1 if x = 1, then y = ???

jimthompson5910 (jim_thompson5910):

you did it right

jimthompson5910 (jim_thompson5910):

another point on this line is (1,-4)

jimthompson5910 (jim_thompson5910):

plot the two points (0,-2) and (1,-4). Draw a straight line through them since we have this sign ≥, which has a line under the ">", we will make this boundary line solid

jimthompson5910 (jim_thompson5910):

yeah because of that underline

jimthompson5910 (jim_thompson5910):

IF there wasn't an underline, then it would be a dotted or dashed boundary line

jimthompson5910 (jim_thompson5910):

we can use desmos to graph https://www.desmos.com/calculator

jimthompson5910 (jim_thompson5910):

type `y >= -2x-2` to mean \(\Large y \ge -2x-2\)

jimthompson5910 (jim_thompson5910):

good

jimthompson5910 (jim_thompson5910):

as for the other inequality y + x ≥ 0 is the same as y ≥ -x (Subtract x from both sides)

jimthompson5910 (jim_thompson5910):

you'll need to graph y = -x then shade above that solid boundary line

jimthompson5910 (jim_thompson5910):

notice how in your desmos graph, the shading is above the boundary line because of the > symbol

jimthompson5910 (jim_thompson5910):

do you know how to graph y = -x ?

jimthompson5910 (jim_thompson5910):

it's very similar to how we graphed y = -2x-2

jimthompson5910 (jim_thompson5910):

if x = 0, then what is y when y = -x ?

jimthompson5910 (jim_thompson5910):

so one point on it is (0,0)

jimthompson5910 (jim_thompson5910):

then if x = 1, y = ???

jimthompson5910 (jim_thompson5910):

yep so we know the two points on it are (0,0) and (1,-1)

jimthompson5910 (jim_thompson5910):

once you have y = -x graphed, you shade above the boundary line why above? because of the > sign. This only works if y is isolated why is the boundary line solid? because there is an underline under the >

jimthompson5910 (jim_thompson5910):

now do both graphs at the same time

jimthompson5910 (jim_thompson5910):

very good

jimthompson5910 (jim_thompson5910):

the final step is to only shade where the two regions overlap one another

jimthompson5910 (jim_thompson5910):

yeah pretty much

jimthompson5910 (jim_thompson5910):

yeah you follow all those steps. Using desmos, or anything like it, is a good way to check the result

jimthompson5910 (jim_thompson5910):

no problem

Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!
Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!