Posts tagged algebra

Posts tagged algebra

*1 note* &

Anonymous asked:
Can you explain the substitution method to me? As simple as you can too please :3 here's an example of what I have to do: y=4x-9 y=x-3

y = 4x - 9

y = x-3

it is very easy, just substitute y from the second equation to the first equation

substituting , we have,x-3 = 4x -9

now solve for x

-3 + 9 = 4x -x

6 = 3x

x = 2

and y = x-3,

so y = 2-3=-1

so your answer is x = 3 and y = -1

in nutshell, you rewrite one of your equations as y = an expression in x

or x = an expression in y using one of the two equations.

put this y =an expression in x or x = an expression in y in the second equation

and if then just solve.

*2 notes* &

smart people, help? Please? These are the last four problems and I have no idea how to do them.

http://askmemathsquestions.tumblr.com/post/31453372065

your answers

(Source: theundyingkindley)

*1 note* &

pure acid is to be added to a 5% acid solution to obtain 95L or 56% solution. What amounts of each should be used? how many liters of 100% pure acid should be used to make the solution?

READY, SET, SOMEBODY SOLVE!!

let x be the number of litres of pure acid and y be the number of 5% acid solution

we have

x+ y = 95……..equation 1

also x + .05y = 0.56(x+y).equation 2

solve both of these to get value of x and y

(Source: frozen-patties)

*3 notes* &

*2 notes* &

okay so i’m dumb and i need help

“For which values of x does 6x(x-3) = 0? Explain your answer.”

so i figure x-3=0 and x=3 but how do I explain that?

actually,

for x = 0 and for x = 3 both

since 6x is multiplied to (x-3)

so for two values of x =0,3, the expression is equal to zero.

also you could elaborate that for these two values of x, this expression( which is a parabolic curve cuts the x axis twice) since it has two real roots

(Source: foreignfennekin)

*3 notes* &

Math people. I need help. I’m doing Linear Programming and I understand how to do it when I am given the inequalities but I cannot make the inequalities when I am given a word problem. It just doesn’t make sense to me. If any of you could help me that would be absolutely wonderful. Here is one of the problems on the assignments.

see if this helps