Question

An algebra test contains 38 problems. some of the problems are worht 2 points each and the rest are worth 3 poins each. A perfect score is 100 points. How many problems are worth 2 points?

Answer 1

you need 2 equations:

38 problems, 2 types

(1) 38=x+y

these have to sum up to 100, so

(2) 3x + 2y = 100

Now substitute one into the other (I suggest (1) into (2)) and solve.

Answer 2

so whats the answer?
i wana make sure i got the right one

Answer 3

post what you did if you want me to check whether it's right or not

Answer 4

3x+2(1)=100
3x+2=100
-2 -2
3x=98
98 divided 3 is 32.6

Answer 5

why did you plug in 1 into y?

Answer 6

didnt u say that?

Answer 7

i meant equation (1), not the number one...

Answer 8

ohhh okay let me trye again

Answer 9

okay

Answer 10

idk what to do! ikno im suppose to plug it in but how?
is this correct:
3x+2(38)=100

Answer 11

nope, you need to isolate a variable, say x: 38=x+y -> x=38-y

then plug that into the second equation

Answer 12

ohhh so 3(38-y)+2y=100

Answer 13

yeah thats it, then solve for y.

once you know y, you can find x (by using the first equation).

Answer 14

remember what those variables represent though

Answer 15

okay thank you soo much do u think u can help me with something else?

Answer 16

and for the answer i got 14

Answer 17

thats right

Answer 18

sure, shoot

Answer 19

okay so write the function h(x)=-5(x-1)^2+3

Answer 20

in standard form

Answer 21

expand this bracket (x-1)^2, then distribute 5 to all the terms within it

then simplify

Answer 22

you should be asking these questions in the math section :P

Answer 23

im new to this so idknow how to work this website out

Answer 24

no worries. it's up at the top, click on "Find More Subjects" and a menu will pop up.

Answer 25

its not letting me it freezes
:(

Answer 26

could u help me with this??

Answer 27

I can't help you with all of that at the moment, but i can give you a link to get to the math section http://openstudy.com/study#/groups/Mathematics