-2x ≥ -x-4 I need the work to be shown please.
First, add x to both sides.
-2x+x≥ -4
good. now combine -2x + x together on the left side
-2x^2?
no. what is -2 + 1?
-1 but where did you get the 1 from?
Remember that x always means 1x. We just don't write the 1 to make it easier, but there is always a 1 behind the x.
-1x≥-4
good just like -2 + 1 = -1 so too -2x + 1x = -1x we just write it as -x
correct
x≥4 thank you
now we have -x ≥ -4 but we want x by itself, not -x
no, not yet. we're not done yet. one more step
oh okay
divide by -1?
now we have -x ≥ -4 but we want x by itself, not -x Since -x means the same as -1x, if we multuiply it -1, -1 * -1x = x, which is what we want.
yes, divide ot multiply by -1 to get rid of the negative. Here's where you need to know something about an inequality that is different from an equation.
and switch the sign
In an equation you can add the same number to both sides, you can subtract the same number from both sides, you can multiply or divide both sides by the same number.
In an inequality, you can add to and subtract from both sides like an equation.
In an inequality you can also multiply or divide both sides by the same _positive_ number, like an equation.
thanks very much :)
The difference with an inequality is that if you multiply or divide both sides by a _negative_ number, the inequality sign switches direction. We have -x ≥ -4 now divide both sides by -1 to get: x <= 4
You're welcome.
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