Solve for x: −3|2x + 6| = −12
start by dividing -3 on both sides, what do u get ?
4.
you mean |2x+6| = 4 ?
Right.
now use this if |a| = b then a= b or a = -b
so if |2x+6| = 4 2x+6 = 4 or 2x+6 = - 4 can you solve these ?
|2x+6| = -12 or |2x+6|= 12
when you split, you remove the absolute signs
and it won't be 12 on right side, isn't it ? we divided by -3 and got 4 on right side...
2x+6 = 4 x = -5
So, x = 5 and x = -5 I just got that.
I mean x = -1
2x+6 = 4 gives x = -1 or 2x+6 = - 4 gives x = -5 so, yes, now its time to verify
plug in x = -1 in your original equation on left side see if you get right side
-3|2(-1)+6| = -12
Yes I do.
now try x = -5
I got 12.
how ? remember |-4| = 4
because |a| = a if a is positive |a| = - a if a is negative
I did -5 x 2 + * -3
+6*
you didn't consider the absolute sign ?
I did everything in the absolute sign 1st.
then mutiplid it by -3.
|2(-5)+6|* (-3) = |-10 +6 | *(-3) = |-4|*(-3) = 4 *(-3) =-12
Aren't we doing the full original equation?
Ahhhhhh.
Absolute number changes to a positive?
so , you just verified that -1 and -5 are both the correct solutions to your equation :) any doubts ?
yes, thats correct... like |-12| = 12 it keeps positive no. as positive |12| = 12
Alright 1 more thing here.
You can help me with it? Compare and Contrast: Two equations are listed below. Solve each equation and compare the solutions. Choose the statement that is true about both solutions. Equation 1 Equation 2 |5x + 6| = 41 |2x + 13| = 28 Equation 1 has more solutions than equation 2. Equation 1 and Equation 2 have the same number of solutions. Equation 2 has more solutions than Equation 1. The number of solutions cannot be determined.
you solve both the equation, in the exact same way we solved −3|2x + 6| = −12
then verify your solutions.
They have the same number of solutions?
thats correct! :)
Awesome, thanks so much for the help.
welcome ^_^
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