Mathematics

How do you solve 2x + y = 7 x – y = –4

2x + y = 7 x – y = –4 a. (1,-5) b. (1,5) c.(-1,-5) d.(-1,5) Anything is appreciated-Add .. its like elimination .. ill show you the steps its pretty self explanitory(: 2x + y = 7 x - y = -4 Okay th

Help me with my math question

A ladder, 8.2 meters long, is placed with its foot 1.8 meters from a wall. How high up the wall will the ladder reach? Give the answer to the nearest tenth of a metre. 10 POINTS FIRST CORRECT ANSWER!

Precalculus math questions

1. Simplify the compound fractional expression. (x/y)-(y-x) / (1/9x^2)-(1/9y^2) 2. Simplify the expression. (1-x^2)^(1/2)+x^2(1-x^2)^(-1/2) / (1-x^2) 3. Find all real solutions of the equation.

Pages per hour? Simple math question

I started reading at 3pm and got done at 6:45 pm. It was 385 pages. How many pages per hour did i read?-(3.75/385) = (1/x) 3.75x = 385 x = 102.666666666666666666666666666666666666… pages per hour-How

What is the proper way to interpret this trig function

f(x) = sin4x² Is f(x) = sin(4)x² OR f(x) = sin(4x²), which way is correct? Is the trig function applied before multiplication or vice-versa?-Or (sin(4x))^2 :-{ Personally, Id assume (which could be

Help Limits in Calculus!?!

lim (7x) / cot( 3x) x->0 lim h (4+2/h^2) x->0 f(x)= x^2+16 lim x->2 f(x)-f(14) / x-2 lim (2x^2) / 1-cos(6x) x->0 Thank you sooo much-7x/cot 3x = 7x/(cos 3x/sin 3x) = 7x sin 3x/cos 3x --> 0 4 + 2

Can anyone tell me what these math signs mean

http://i.imgur.com/bX2zS.jpg-1) Approximately (not EXACTLY equal to, but really close) 2) if and only if-The first one means approximately. I dont know the second one. EDIT: I found the second one o

If tan^2 A = 5/9 and A is between 3pi/2 and 2pi what is the value of cos A

So A is in quadrant 4 so tanA tanA = -√(5)/3 and tanA = opposite/adjacent so opposite = √5 adjacent = 3 Hypotenuse = √(5 + 9) = √(14) cosA = adjacent/hypotenuse cosA = 3/√(14) = 3√(14)/14-First,

Difference between inverse and direct variation

Can someone please explain to me how i can tell whether a problem is Inverse, direct, or neither? I need help especially on these two problems: 1.x=-7 2.3x-3y=0-Basically, direct variation means that

| 4-1/4x | ≤ 5 <--- Solve

Solve please-| 4 - .25x | ≤ 5 a. 4 - .25x ≤ -5 -.25x ≤ -9 x ≤ 36 b. 4 - .25x ≤ 5 -.25x ≤ 1 x ≤ -4 Final answer: {36, -4}

The variables x and y vary directly and y=-6 while x=1/4.How can I write an equation that relates the variable

If x and y vary directly, then y = kx Sub in x = 1/4, y = -6: -6 = k/4 k = -24 So y = -24 x

Algebra 2 Honor Help Needed!!

Hi Im new to this forum and Id have a question about Alg. 2 The question is: put this into interval notation: all real numbers greater than or equal to 7, but not equal to 13. I answered it as [7, Po

Math question : I think I got the right answer, but mathxl said the answer was wrong !

Frances left a 19% tip on a meal. Including the tip, its cost was $40.46. What was the cost of the meal before the tip? Here is what I did : Supposedly, x : the total cost ($40.46) ; y : the tip [ 19

Bijection using the normalizer subgroup

Let the normalizer of H in G be N(H). let X be the set of left cosets in G of the subgroup N(H). Let Y be the set of all subgroups of G which are conjugate to H. Show that there is a bijection between

Factoring question, please help!

Can someone please help me with a factoring question? 2c^2 + 6cd - 8d^2 answer: 2(c + 4d)(c - d) Your help will be most appreciated!-Original: 2c^(2)+6cd-8d^(2) Factor out the GCF of 2 from each t