Answer:87.63
Step-by-step explanation:
Answer
a. The backpack is $4.50
b. The sweatshirt is $2.70
Step-by-step explanation:
a. 30 x 0.15 = 4.50 (The 0.15 is from the price you are actually paying for the item. Because the item is 85% off, you are paying for 15% of the usual price. 15% as a decimal is 0.15 so you multiply that to the original price to find the amount u will pay.)
b. 18 x 0.15 = 2.70
I won't answer them all for you (don't want to cheat - need to learn something).
But for the first one given:
<span>-2x-9y=-25
-4x-9y=-23
you set up either x or y (which ever one you want to eliminate) so that one of them cancels.
So this one is easy - you just have to multiply an entire row by negative (doesn't matter which one) - so that the y's will be + and -
Since they're both 9 and they're subracting NOW - you can eliminate the y value. Now add/subtract the x's. So it'd be -2 or 2 depending on how you eliminated y. Then add the number outside of the = sign. Now just solve for x. After that plug in whatever you got for x into both of the rows. Then find the y value.
Hopefully this wasn't confusing -- reply if it is and I will try to simplify. I can give you contact if you need help with the rest
Good luck!</span>
Another user previously answered this same question and had a good rating, his answer was as follows:
"{-9; -6.5; -5.2}"
Which I suppose would be answer D.
- Hope it helps.
5x²+y²=3
by implicit differentiation we shall have:
10x+2yy'=0
the second derivative will be:
10+2y"=0
2y"=-10
y"=-5
