2.5(4k+2)=12k
So on this expression for example, how do i figure out on what side i need to move everything to that will give me the correct answer. You move the k to the left side and it comes to -2.5 which is incorrect, but if you move it to the right side then it comes to 2.5 which is the correct answer. Please help it make sense to me. Ive never been good at algebra and im trying to use khan to get me a headstart before i start college again, thank you
It doesn't matter which side of the equals sign you move things around as long as you're careful with your signs. Both sides should give you the same answer. I'll solve it in both ways below.
Solving for "k" (moving "k" to the left side of the equals sign):
[original equation] 1.5(4k+2) = 12k
[multiply the 1.5 into the parenthesis] 6k+3 = 12k
[subtract 12k from both sides] 6k+3-12k = 12k-12k ; [you get] 3 - 6k = 0
[subtract 3 from both sides] 3 - 6k - 3 = 0 - 3 ; [you get] -6k = -3
[divide both sides by -6] -6k/-6 = -3/-6 ; [you get] k = 1/2
Solving for "k" (moving "k" to the right side of the equals sign):
[original equation] 1.5(4k+2) = 12k
[multiply the 1.5 into the parenthesis] 6k+3 = 12k
[subtract 6k from both sides] 6k+3-6k = 12k-6k ; [you get] 3 = 6k
[divide both sides by 6] 3/6 = 6k/6 ; [you get] k = 1/2
So in both cases, as you can see above, you get "k=1/2". Just go slow and make sure your signs are right as you move things around. But there is nothing tricky about it here, both sides of the equal sign works.
Hope this helps!
Please sign in to leave a comment.